Update Wordpress/API for custom header

Description

We have a Wordpress website that connects to an iOS and Android app so that users can login on the app and view the data that is assigned to them. This has all been working fine until recently when we updated Wordpress to the latest version as well as PHP to 8. Now, when trying to access it we're getting a 401 error from the API. We have been using a modified version of this plugin: https://github.com/WP-API/Basic-Auth
Basically, the app sends basic auth via a custom "X-Login” header which our developer wrote to get around an issue with the basic auth plugin. We just need to extract the login from the "X-Login" header and log the user in for the duration of the request. So we need someone to help update the Basic Auth plugin to allow for this.