Employment Reference

Me and my partner are currently undergoing referencing for a flat , but my partners employer will not fill out external forms and will only send there only template over with the relevant information on this . Openrent will not accept this as a valid reference and is going to lead us to failing employee references. Has anyone experienced this ? We are unsure on what to do

Searchig for similar questions in the past on this forum, I see this;

So, there must be another option. Has the employer checked the email to see if there are options for replying?