While @Alex program is awesome figured out a simpler way to have changes in Syncthing immediately show up in Nextcloud.
If add Syncthing folder as an external local folder in Nextcloud all changes made through Syncthing will immediately show up in a Nextcloud instance.
Pros to using @Alex program is that (think) it integrates with Nextcloud/ owncloud trash, versioning, and maybe activity so it is a more complete solution integration solution than the above method. Cons are that @Alex program adds even more complexity. Nextcloud trash and versioning still work with the external local folder method but only changes made in the Nextcloud web interface will utilize the Nextcloud trash and versioning. Syncthing changes will only utilize Syncthing file versioning.