Basic Bulk Buy Crates can be purchased in a number of Shops, in fact MOST shops have the Basic Bulk Buy Crate. There are Carts scattered around the island(s) that sell them. One is located in Icehelm, in the back right corner, behind The Big Forge, another is located along the waterfront near the Corestone Shop, and a 3rd is located past the two shops in Ember Cradle towards the town (not up the hill). I believe there may also be one in Bridgepour, along the main road, near the river.

In addition to installing the Bulk Buy Crate MOD, you also need to install the HML Loader MOD. It's required for the Bulk Buy Crate MOD. My recommendation, if you haven't installed the HML Loader MOD would be:

1. Save out of your game and quit Hydroneer
   
2. Start Hydroneer
   
3. Go into MOD's and REMOVE the Bulk Buy Crate MOD
   
4. Quit Hydroneer again and restart it
   
5. Install the HML Loader MOD and install the Bulk Buy Crate MOD and make sure they are Enabled
   
6. Quit Hydroneer yet again
   
7. Restart Hydroneer and then Load your Save.

All these steps are to clean things as much as possible and avoid "contamination" from something that wasn't working correctly.

EDIT/NOTE: I use the Bulk Buy Crates all the time and they're scattered around all my Mine and Farm sites. I have larger Bulk Buy Crates with hundreds of Pipes stored in them, in case I decide I want to change my Mine's configuration. I find it easier to keep a supply of Pipes available at each Claim, rather than hauling a few Crates around all the time...

what to do if the mod does not work and says that the mod version is not compatible?

Yeah, it does seem that the Bulk Buy Crates and Storage Crates MOD's stopped working with the Volcalidus Update. It would be up to the MOD Creator to repair the MOD...

I'm pretty certain the Storage Crates MOD was built by one of the Dev's, but the Bulk Buy Crates was designed by a player. It may take time for them to fix the MOD if it's even possible...