Genie App and security help!!

Please help!  I bought the router for my apartment, it is registered under my name and I want to use the genie app to control the wifi. I think one roommate has connected to the genie app and is messing with the network map and who has internet access.  This is my router so I want to make sure that only I have the power to do that with the genie app.  But I do not know how to do that.  The password for the genie app is automatically the wifi password.  I do not want to change the password on all of my roommates, I just want to be the only one in control of the router and who has access via the genie app.  I understand this may be confusing but please answer the best you can, thank you!