Upload local site files to Flywheel staging site?

I started using Local a couple weeks ago and have come up against the “error establishing database connection” snafu. I posted a topic yesterday but haven’t received any assistance. I’ve been searching through the other related support posts in the community and it appears that resolutions to the issue are far more technical than I want to grapple with as I don’t have time to mess around with this. I need a reliable solution that just works, so I’d like to upload my site files to a FW staging site and work from there. I really don’t want to lose all of the work I’ve done to date in rebranding my client’s site. Is there a way to upload the site files from my directory to Flywheel?

I’d really appreciate your guidance here. Thank you.