Run through this checklist:
1. Caps Lock — is it on?
2. Correct email address — are you using the address you were invited with?
3. Forgot password — click the link on the login screen for a reset email
4. Browser cache — clear cookies for `senly.io` and `app.senly.io`
5. Different browser — does it work in Chrome or incognito? Then it's in an extension
6. Time synchronization — if you use 2FA, sync the time on your device
Still stuck? Ask a fellow admin to reset your password via Admin → Users.