I would still use the deeplink module. But you still need to create a pending link in App B. Depending on how much data either use an API for this to create the pending link in App B or also use a deeplink for that.
So in App A the link is created with certain data. Then from App A use a deeplink to transport this data to App B with probably two parameters: the page that needs to be shown and the unique ID that is also in the link to the anonymous user. That second deeplink in App B creates a pending link so that the link to the user becomes valid in App B.
Regards,
Ronald