please try turning on SEF with htaccess file on your Joomla website (then you will get such links as we have on our website - for example my profile url is: www.joomlapolis.com/my-profile/userprofile/nant )

It's impossible without custom URL rewrite rules to ensure those URLS are sent to the correct location. By default URLS as constructed as follows with SEF enabled.

site/menu-alias/task/username
www.example.com/community/userprofile/demouser

You'd need to make a custom rule in htaccess to change this to your liking. Am not too familiar with htaccess rewrites so wouldn't know what to suggest, sorry. Some SEF extensions may also allow you to do this, but we don't support SEF outside of Joomlas.

You need to have a Joomla menu link to CBs profile (this link is mandatory) that is public and published. The alias would then be used in your SEF. I recommend the below SEF configuration.

Joomla Backend > Site > Global Configuration > Site > SEO Settings
Search Engine Friendly URLs: Yes
Use URL rewriting: Yes
Adds Suffix to URL: No
Unicode Aliases: No
Include Site Name in Page Titles: No