Where is the beam to be replaced? I see top plates and a doorway header, but no beam to be replaced.

You'll have a hard time finding someone to come in and just install a beam when someone else has done thee work up until now and someone else will do thee balance of the work. He cannot charge you enough to make it worth his while.

Is there a permit for this job and the beam was approved by the building department?

I suspect a bearing wall is being replaced with a beam

Perhaps it could be an LVL beam

What does the wall support?

A structural engineer who consults on residential work should be able to recommend contractors with the required skill set. You might also check with your local building dept. Most won't recommend a contractor, but if you're nice, the folks at the front desk might whisper a name or two.