In this context: lemmy.world/post/48453617 I think it’s just fine.

OP is not asking anyone to buy their product. OP is not shilling their product. OP is asking those who run the *arr stack, and who are interested, to beta test the product, and in return, the beta tester gets the final product for free. This is how beta testing works. Where else would be a good place to have people beta test a product that integrates with what the majority of selfhosters run (*arr stack in this instance) than in a community of selfhosters.