linkedin.com
In short: LinkedIn (linkedin.com) accepts company page/articles. It is free + paid tier to submit, takes real preparation and a written pitch, and scores 78/100 on our impact ranking (high impact).
Create company page and publish case-study posts.
Use real company details; publish useful posts.
Priority is high, which sets the band. It is free + paid tier and involved to complete, which adjusts it within that band. The score ranks your queue — it is not a measure of domain authority.