This seems to be a common question but I can't quite nail the answer. I have an i-frame on my site and it displays the domain's Roundcube webmail. That's all fine, but it won't allow the user to insert their password, rejecting the action as invalid.
Any easy fixes? Many thanks.
It could may be the 'x_frame_options' or 'session_samesite' config options you need to adjust. Details of the issue would help, what is reported in the browser (and browser console) or in the Roundcube error log?
iframes are often messy when it comes to browser security, the more info you can provide the more likely someone has some advice for you.