Transmission RCP & SSL

Hi everybody,
I have a problem: I want to remotely access my transmission webpanel via SSL (I installed a Letsencrypt certificate for my OMV, which I access via a no-ip domain).
Under Openmediavault 2 the transmission admin panel could be accessed as a child page of the OMV admin panel itself, so there was no problem, but under OMV 3 it will open an external link which will not be accessible as a secure page.
I digged a bit and found that nginx could be configured to do the trick, but I have no idea of how to do it: tried to follow some procedure, but with no luck. I am not new to linux, but this matter is a bit out of reach for me.
Could anyone help me please? Thank you very very much!