[keycloak-user] Convert Keycloak tokens to "cookies" for a Spring-boot app

I have a backend server secured using Keycloak Spring web security adaptor. The UI uses the cookies to store the session reference. Now another website would like to implement "SSO" - have a link in their page to connect directly into my application. This other website is able to obtain access/refresh tokens directly from the Keycloak. How can I "convert" the access token to a cookie, which will be recognized by my Spring backend?