How can I activate/deactivate the connection to EWP Network?
You can activate/deactivate the Inter-institutional Agreement API via the Erasmus Dashboard EWP Settings section - see a tutorial here.
And you can see the APIs activated for your HEI here: https://registry.erasmuswithoutpaper.eu/coverage as well as the party representing you in the EWP Network here: https://registry.erasmuswithoutpaper.eu/manifestsOverview - just search by the SCHAC code.