Hi @Carlos01.
I know that this would be easy if we can extend the 60-day limit condition in QuickBooks Online (QBO) to convert the desktop file.
Calling the Care Support team can be the best option to extend its limit when your QBO account is unused or empty for more than 60 days. Thus, they have tools and you can request them to override the maximum limit requirement and successfully convert your file to QBO.
Otherwise, you may need to cancel this subscription and get a new QBO account and start all over again for the conversion. You can also check the solution shared by my peer, @JasroV, to ensure a smooth transition.
I've added resources/articles for you to foresee the conversion process:
If there's a lot of data to transfer, you can use the Condense Data utility in QBDT to reduce your file's overall size while keeping all your data in detail.
Please know that I'll be here to help you if you have other concerns with the migration process. Have a safe day ahead!
