Allow Members to Set Their Custom Password On Sign-up
To allow a member to set his/her custom password during signup, please go to Optimizemember >> General Options >> Registration/Profile Fields & Options. Look for the "Allow Custom Passwords During Registration" option and then set this to "Yes ( allow members to create their own password during registration )".
Don't forget to hit the Update button at the bottom of the page to store your changes.
Please note that if this option is enabled, the user will no longer receive an email containing the link where they can set their password.