I was able to get pcloud Webdav to work well first try. It just required me setting the uri to https://webdav.pcloud.com and then using my pcloud credentials. So nice.
Although, if you want to fill a specific folder, you will need to add its path to the end of the uri.
Mine for the sake of being consistent with what is used on OneDrive is:
https://webdav.pcloud.com/Apps/Joplin/