You may want to check with an accountant for the details, but basically if you're the only member of the SRL (LLC) it should be straightforward.
You have to report all your earnings on Upwork as the Company's earnings. There could be an issue with invoices since Upwork doesn't send you any copy of the invoices they send to your clients on your behalf. But again, your accountant is the right person to consult with.
"Where darkness shines like dazzling light" —William Ashbless