I had a problem where the Update Manager was not working on a specific host, VMware support wasn’t really helping so I decided to ask around and found that it can be done in the command line

Steps

1. Download the Depot
2. Upload the file to a storage that the host can access
3. Put the host in Maintenance mode
4. SSH to the host
5. View the uploaded zip/file
   esxcli software sources profile list -d /vmfs/volumes/VMFS-Identifier-here/VMware-ESXi-7.0U3m-21686933-depot.zip
   (how to find the “identifier” login to vSphere Client, Click on the storage, Summary Tab, And look for “URL:” /volumes/identifierlisted
6. This will list all the profiles inside the zip file
7. esxcli software profile update -p ESXi-7.0U3m-21686933-standard -d /vmfs/volumes/VMS-Identifier-Here/VMware-ESXi-7.0U3m-21686933-depot.zip
8. Reboot