Hello,
It depends on what game or services you're trying to post the service.
For example it's an account upgrading on APEX LEGENDS, then suppose to be you should post your services here :
[Only registered and activated users can see links. Click Here To Register...]
Just make sure before posting that you read the rules about selling services and products. Epvp is strict on rules especially on blackmarket, They won't ban or remove the post as long as it's within the website rules.