Create interactive online form based on Google App Script - repost

Dear Freelancer, I would like to work with somebody to build a more interactive form based on Google App script that is presented on a site and pulls and enters data into Google trix pages in the background. Basically, I have some data of the people who should take the survey, like department, group they are working with etc and once they get the survey I want these data fields to be populated automatically from a trix in the background. If the data is correct then we go to a question screen, if not then we allow them to update the data which then should update the data in the trix as well. The question section should be similar interactive, certain questions should trigger additional questions etc. The trix where that data is stored in the background should also calculate a score based on the answers which then is shown on the last page of the form / survey as a result. Not sure if that all makes sense, I have the concept and flow ready but I got stuck on the actual implementation. This needs to be App script as my company is using this and I want to be able to make amendments when necessary. Looking forward to bids. Thanks and Regards, Alex