Using the NextCloud app in a Windows Environment to sync all files in a local server

I have downloaded and installed the Windows application and have attempted for days to synchronize all the files in the local Nextcloud server to a machine so that I can migrate from this platform. It checks for changes for literally days and downloads nothing to the computer. The manufacturer suggest someone here might have a suggestion. I’ve waited over 6 days of it checking folders with no synchronization. I’ve tried multiple admin users. Is there a way to go in the backdoor from a windows environment to the Linux server the NexCloud server is on and pull the data en masse?