How do I mount a Synology remote folder on iPad running iOS 13.3

I have a number of shared folders on a Synology drive which I can mount without any issues on a couple of different Macbooks running different versions of Mac OSX. I am assuming the folders are published using CIFS/SMB but I cannot mount them on my iPad using the file app browser. The iPad puts up a generic and not particularly helpful error dialog "There was a problem connecting to the server. Check the server name or IP address and then try again..."

I can connect to the Synology home page using a browser so network connectivity between it and the iPad is OK. Running "nmap -p139,445 --script smb-enum-shares " indicates that shares are up on both ports 139 and 445.

Try connecting manually.

In the top left portion of the screen, select the menu button at the top (three dots in a circle) and then select “Connect to Server”. Try using the IP address first. Make sure you firm the URL correctly:

smb://<Synology IP Address>

You should be asked for username and password.

If that works, try it with the DNS name next.