Margrét Blöndal (operations manager) and Sölvi Signhildar-Úlfsson (guide) of Icelandic Mountain Guides seen on FB video. They offer both single day and multi-day tours. There was a webinar on March 5, 2024 at 12:00 EST on "Tips for Your Iceland Travels: Q&A With Local Guides" presented by 57hours. 57hours lists multiple hikes in Iceland from 1 to 12 days.
One of the most popular hikes is the Laugavegur Trail. See a video here.