Signal is working on a way to sign up without a phone number. The feature has not yet been officially confirmed, and it is not yet known whether it will be available to all users or in what form.
Do you have google play services installed? If not, your power optimisation settings might prevent signal from running in the background, which it needs to to receive messages
Do you have google play services installed? If not, your power optimisation settings might prevent signal from running in the background, which it needs to to receive messages