Hi, I would like to use hotspot with usermanager in routerOS v7.7. Hotspot already has the basic configuration, but how to interface it with user manager? also from LAN if I call the usermanager web I get error 404

user login

Your last screenshot 172.16.20.1:8080/userman,what do you need to archieve in ROS7 with that address? That page address is for previous version of User-Manager, will not work with UserManager at ROSv7.
And until now ( v7.8 ) as far as I know, hotspot redirection page for customer still somehow broken. Customer will still get the hotspot login page when they first login to the AP. But as soon as they login, (again as far as I know, enlightment me if someone know how to fix), entering hotspot dns (your case is "http://green.hotspot" or even with ip) will make address not found error.

Your first post :
* First, better use default login page of hotspot ROS7.
* Next set the hotspot with local user first and make sure it run fine. Turn off all related User-Manager setting plus RADIUS setting. Enable that local hotspot user abbio90 and make sure that user can login the hotspot. If cant, something messing with your hotspot setting, fix it first before integrate it into UserManager Authentication.
* Then when local user run fine, so you can proceed with using User-Manager.
Assume your hotspot local user can login now setting the RADIUS ON+User manager

First better to link User Manager Group with Hotspot User Profiles. You have with "default"
Link a user-manager group to that hotspot profile
/user-manager user group add name="greenhotspot" outer-auths=pap,chap,mschap1,mschap2,eap-tls,eap-ttls,eap-peap,eap-mschap2 inner-auths=ttls-pap,ttls-chap,ttls-mschap1,ttls-mschap2,peap-mschap2 attributes=Mikrotik-Group:default
Then link the user that you create, I take sample of user 'abbio90', with
/user-manager user add name="abbio90" password="abbio90" otp-secret="" group=greenhotspot shared-users=1 attributes=""
Next I see you have create UserManager Profile with
/user-manager profile add name="prof1" name-for-users="abbio90"
Now link the user and the profile
/user-manager user-profile add user=abbio90 profile=abbio90
Last enable UserManager with using User-Profile
/user-manager enabled=yes use-profiles=yes

Try to login hotspot with user abbio90 password abbio90.

ok, i managed to login with user manager user. I attach the current configuration.
There remains the problem of reaching the user-manager web page

If 'user manager web page' you mean as previous ROS6 UserManager for managing userman AKA 'http(s);//hotspotdns/userman", in ROS7 it doesnt exist anymore. If you insist about that better you go back to ROS6.
At ROS7 UserManager, all managing will be done from Winbox via terminal or directly to UserManager Menu.

Please read more here https://help.mikrotik.com/docs/display/ROS/User+Manager

The only web page interface in ROS7 UserManager is http(s)://hotspotdns/um you can read about that at Web Interface section...
"Each user has access to his personal profile using a WEB interface. The WEB interface can be accessed by adding "/um/" directory to router's IP or domain, for example, http://example.com/um/. Note that the WEB interface is affected by IP Services "www" and "www-ssl". The WEB interface can be customized using CSS, JavaScript and HTML."
For me this section still cant be done, due always error to try open hotspotdns via web browser, after login.

I confirm, the page is accessible. What if I want to manage PayPal payments after the ticket issued at the first login has expired?

Hmm there must be something at my hapAC3. Somehow I netinstall it and re-setting all from scratch, I managed to showing my hotspot login/status screen even after my device login.

For paypal I never set it up. Maybe other expert can help.

Best regards.