You can create FRS 105 Micro Entity Accounts for the limited companies by changing the company size in the company report settings. To do so follow the navigation as shown below.
Navigation: Accounts Production >> Settings >> Report Settings >> Company Info >> Report Information >> Edit >> Change the Company size and Taxonomy to FRS 105 >> Save
Once you make the changes please regenerate the report so the changes are reflected.
You can click on this link to redirect you straight to the page you want to edit.