if you are not receiving the otp when you attempt to login this could be caused by a few things.
1. rate limiting or tagged as spam - in order to limit the possibilities of the OTP system being abused their are limits in place on how many login/otp sends can occur over a period of time. these values are being optimized over time based on feedback and patterns we see. to help avoid this happening to you, refrain from multiple log in and log outs in short time frames. logging out and in is typically not going to resolve any bugs or issues you encounter and as such not needed. it is best to open a support ticket to seek resolution. attempting multiple logins over and over again will in fact increase the lockout time for receiving otp again.
2. your country has not had otp enabled for it as of yet.
for all cases if you are not receiving the OTP please submit a support ticket that includes your phone number, carrier and country and the support team can investigate and inform you of what is going on.
in most cases your patience and avoiding multiple login/logout events in short time frames will self resolve the issue.