**As** an administrator setting up the OpenProject-Nextcloud integration setting up the OpenProject side
**I want to** have a second option to use OIDC based access tokens instead of OAuth2 access tokens when I also use and Begin of the insertionIDPEnd of the insertion Begin of the deletion idPEnd of the deletion like Keycloak for single sign on (SSO)
**so that** not each user needs to got through the OAuth grant Begin of the insertionflow.End of the insertion Begin of the deletion flowEnd of the deletion

**Acceptance criteria**

* In the files storages settings for Nextcloud, there is a new step 2 in which the admin is asked what type of integration she wants to setup

* Two-way OAuth2 authorization code flow (default)

* OpenID Connect (OIDC) Begin of the insertionvia Token ExchangeEnd of the insertion Begin of the deletion - KeycloakEnd of the deletion

* If the admin choses "OAuth2" then the step 3 will be "OAuth applications" with the sub-steps "OpenProject OAuth" and "Nextcloud OAuth" as we currently have them.

* If the admin choses "OIDC" then it will show information text with a link for further documentation.

* It shows a warning if there is no OIDC configured (on OpenProject's side).

* It tells that the setup was only successfully tested with Keycloak and not with other OIDC providers.

* It tells to follow the setup instructions in the docs on how to configure OIDC in OpenProject and how to configure the OIDC provider and offers a link to the correct OpenProject docs.

* The admin is required to select an OIDC provider. The admin can choose from configured OIDC Begin of the insertionproviders capableEnd of the insertion Begin of the deletion providerEnd of the deletion of Begin of the insertionToken ExchangeEnd of the insertion Begin of the deletion type "Keycloak" in OpenProjectEnd of the deletion (dropdown).

* The admin needs to enter the OIDC client ID of Nextcloud (text input)

* The save button should be labeled as "save" (to be confirmed)

* The admin needs to be able to switch between OAuth2 and OIDC on existing file storages, to provide a migration path.


**Figma**

workPackageValue:"Figma wireframes"