I've heard about this mod from YouTube and it sounded pretty sick so I changed from fabric to neoforge to use it but i cannot detect the biomes anywhere at all using /locate and the cave biome map, so is there any config to make the biome spawn more commonly, tell me step by step how to make it more common by config.

As far as I know. There're 4 ways:

1. edit config file: it should be in .minecraft\versions[your version]\config\alexscaves_biome_generation, which you can find 5 json file, open them, "alexscaves_rarity_offset" controls the rarity, change its value to 0 should increase the chance of cave generation.
2. use the mod : https://www.curseforge.com/minecraft/mc-mods/tact
3. some old version mod cause bugs, the caves are not just RARE but DONT generate at all, try update your Alex Caves and Citadel
4. the Final solution is this mod https://www.curseforge.com/minecraft/mc-mods/alexs-caves-dimension ,but it is unstable and there are some bugs.

It's challenging to test the effectiveness of the first method, but I guess it indeed works.
The second way seems to solve the problem, yet I'm equally unable to test its effectiveness.
I actually encountered the third scenario, where using both the first and third methods made it easy to find various caves in the new save.
The fourth method can "guarantee" access to the caves of this mod, but you must enter other worlds through a portal