How to define a new data source?

After reading the Sen4cap v-3 user manual, I tried to install the Sen4Cap on Centos 7.9 and it installed successfully.
My question is:
How to setup a new data source for Sen4Cap web GUI alongside the defaults ones? If it is not possible to do this by web GUI how to do that via terminal? In particulate, I want to use Sentinal-3 data. (I have visited the “” site but did not understand how to give Sentinal-3 data access to Sen4cap software). Anyway, I would be thankful for your help related to web GUI or the terminal instructions to add a desired data source.
The best

As fare as I know you can’t use sentinel-3 data as an input for Sen4CAP. Sen4CAP uses Landsat, S1 en S2 as input. Also doesn’t really makes sense to use S3 data which measures sea surface topography, sea and land surface temperature and bunch of other things. The Sen4CAP project aims at providing to the European and national stakeholders of the Common Agricultural Policy validated algorithms, products, workflows and best practices for agriculture monitoring relevant for the management of the CAP. S1, S2 and Landsat8 are from publicly available data the best suited for this particular purpose.

Best regards,