Yes tester calls can only be put on Ribblr if users are able to apply on Ribblr, directing potential testers to apply elsewhere without being able to apply on Ribblr is not allowed
Feel free to read the testing guidelines (just click the text and it’ll send you there) for any other questions or concerns you may have about testing 
Don’t hesitate to ask any other questions if you have any or if you need immediate answers feel free to look in the help center and the community with keywords if needed