You probably logged in using a different account or user. For example, the admin user (first person to add the SoyMomo) logged in through a Facebook account, but you now logged in using an email (secondary user). It is also possible that you made a typing mistake when writing your email.
If you are not the first user, the admin of the SoyMomo has to go to the App> Lateral menu > Pending requests and accept you.
Note: If you still have problems, in either case, write to us at firstname.lastname@example.org so that we can help you.