Handy Buy Website Issues

1) Providers Access on "Access to Suppliers" _ location of access on the Site: [login to view URL] This access is exclusive for providers and is controlled by the "Custom" plugin (MyHandyBuy Custom Plugin) which is a plugin made to Handy Buy by a third party; what happens is that it does not allow registering or logging in even if this is correct in the admin of provider users on the site. Of course I have test provider record 2) Active PHP session detected_ I don't really know why it is currently like this, though; If the update of PHP to the latest version is required, it could break something on the site that is made in a customizable way such as the "Custom" plugin and therefore said update, it would be convenient to review how it can be done so that this does not happen or what options they can be implemented so that this does not happen (for example on the Test Site). 3) The Rest API has encountered an error_ This has always been there and needs to be fixed. 4) Your site was unable to make a loopback request_Same 3) 5) Your site is running an old version of PHP_ however it is possibly related to 2) or not but it is important to see how it does not break the processes that the "Custom" plugin executes