Submit Corporation Tax Return through BC Easyfiler

Hello. I have prepared and submitted my company accounts and have them in HTML format. I have also signed up with BC Easyfiler and paid the £15 to submit a tax return. However, I don't know how to create the file specifications and submit them to BC Easyfiler to then submit to HMRC. Please see attached screenshot of information required by BC Easyfiler. I am looking for a quote to create the tax return from the accounts in HTML to XBRL, submit them to BC Easyfiler and then go on to submit them to HMRC.