Press ctrl + shift + c all at the same time on your keyboard.

When testingcheats is on (put testingcheats on in the console and press enter), interactive objects will have new interactions when holding shift before clicking on them. Your lot's mailbox will also include some useful ones, aswell as clicking on a sim. Testingcheats also allows access to enabling other cheats, like sv_cheats in a source game.

kaching: Gives current household §1,000.
rosebud: Gives current household §1,000.
motherlode: Gives current household §50,000.
money <amount>: Sets current household funds' amount to the input value. Requires testingcheats to be on.

fps {on/off}: Toggles on/off the fps meter.
fullscreen: Allows to switch between fullscreen and windowed modes.
help: Shows up available cheats.
headlineeffects {on/off}: Toggles thought bubbles and the Plumbob.
resetsim <sim name>: Resets selected Sim on the current lot, with neutral motives.
quit: Exits the game.
testingcheats {on/off}: Enables additional "testing" cheats, not intended for use.
freerealestate {on/off}: Allows you to move Sims in any house, for free.
casclockspeed {0-10}: Changes speed at which time passes in CAS.
hovereffects {on/off}: Toggles glowing appearing around Sims and objects when you hover your cursor over them.
sims.get_sim_id_by_name <Sim's/Pet's name>: Shows Sim's or pet's ID.
version: Shows game version.
bb.moveobjects: Allows you to place an object neglecting placement rules, anywhere. Use Ctrl+9 and 0 to change height.
bb.showhiddenobjects: Allows you to buy Debug items in Buy mode, like Invisible Ceiling Lights.
bb.ignoregameplayunlocksentitlement: Unlocks every Career Reward object
cas.fulleditmode: Allows you to change everything in Create a Sim

cas.unlockbytag GP09: Unlocks all Journey to Batuu items in Create a Sim

cas.unlockbytag SP17: Unlocks all Nifty Knitting Stuff items in Create a Sim
cas.unlockbytag SP18: Unlocks all Paranormal Stuff items in Create a Sim.

death.toggle {true/false}: Toggles Sims' death possibility. Has to be reinputted everytime the game is loaded.
sims.remove_all_buffs: Removes all the moodlets from the current Sim.
households.autopay_bills: Bills will no longer arrive to your household.
ui.dialog.auto_respond: Turns auto respond function on.
sims.spawnsimple <number>: Spawns selected number of Sims.
objects.consumables_infinite_toggle {true/false}: Dishes are infinite and don't spoil. Has to be reinputted everytime the game is loaded.

careers.promote <career name>: Promotes your Sim in the specified career (Your Sim must be working in it). If used while at the top in a career, the Sim will instead get a pay rise
careers.demote <career name>: Demotes your sim in the career. Same rules apply.
careers.add_career <career name>: Makes your Sim join the specified career.
careers.remove_career <career name>: Makes your sim leave the specified career (Your Sim must be working in it)
sims.modify_career_outfit_in_cas: Allows your Sim's career outfit to be changed. This cheat must be re-entered after promotion.
Accepted careers' names are, as follows:

detective, doctor, scientist, socialmedia, careers_adult_critic, activist, secretagent, techguru, painter, entertainer, astronaut, culinary, writer, business, athlete, highschool, gradeschool

stats.set_skill_level <skill name> <level>: Gives your Sim the skill that was inputted.

Accepted skill names are, as follows. (Add Major_ before every skill name)

Acting, Archaeology, Baking, Bartending, Charisma, Comedy, Creativity, Dancing, DJ, EquestrianSkill, Fabrication, Fishing,
Fitness, FlowerArranging, Gardening, GourmetCooking, Guitar, Handiness, Herbalism, HomestyleCooking,
Knitting, Logic, Mental, Mischief, Motor, Painting, Parenting, Photography, Piano, PipeOrgan,
Programming, Reaping, Research, Robotics, RockClimbing, RocketScience, Social, Singing,
Skiing, Snowboarding, Veterinarian, VideoGaming, Violin, Wellness, Writing

If cheat does not work, use stats.set_skill_level adultmajor_x for adult skills, stats.set_skill_level skill_child_ for kids' skills, and stats.set_skill_level skill_toddler_ for toddlers' skills.

ModifyRelationship YourSimFirstname YourSimLastname Sim2Firstname Sims2LastName # Relationship_Type

The # will represent the positive or negative value of relationship from 1 - 100

Relationship Type:-
LTR_Friendship_Main - normal Sim to Sim friendship
LTR_Romance_Main - Sim to Sim romance
LTR_SimtoPet_Friendship_Main - A Sim's relationship with a pet

stats.set_stat lifeSkillStatistic_Empathy 100 – Increases the Empathy value.
stats.set_stat lifeSkillStatistic_Manners 100 – Increases the Manners value.
stats.set_stat lifeSkillStatistic_Responsibility 100 – Increases the Responsibility value.
stats.set_stat lifeSkillStatistic_ConflictResolution 100 – Increases the Conflict Resolution value.
stats.set_stat lifeSkillStatistic_EmotionalControl 100 – Increases the Emotional Control value

traits.equip_trait GoodManners – Grants the Good Manners trait.
traits.equip_trait BadManners – Grants the Bad Manners trait.
traits.equip_trait LifeSkills_Responsible – Grants the Responsible trait.
traits.equip_trait Irresponsible – Grants the Irresponsible trait.
traits.equip_trait Mediator – Grants the Mediator trait.
traits.equip_trait Argumentative – Grants the Argumentative trait.
traits.equip_trait Compassionate – Grants the Compassionate trait.
traits.equip_trait LifeSkills_Unfeeling – Grants the Insensitive trait.
traits.equip_trait EmotionalControl – Grants the Emotional Control trait.
traits.equip_trait Uncontrolled – Grants the Uncontrolled trait.

sims.give_satisfaction_points <amount>: Gives your Sim a precise amount of Satisfaction Points.
aspirations.complete_current_milestone: Instantly completes the Sim's current aspiration milestone.

https://sims.fandom.com/wiki/The_Sims_4/cheats