QuickBooks does not have one export-everything button. It has five exports in five places. Here they are.
Reports (the ones that matter)
Reports, then run and export to Excel: Profit and Loss (by year, by month columns), Balance Sheet (as of each year end), General Ledger (all dates), Trial Balance (each year end), Transaction List by Date (all dates).
Bank transactions
Transactions, Bank transactions, choose the account, Categorized tab, select all, export CSV. Repeat per account. This is the raw data you can re-import anywhere.
Lists
Reports, Account List (your chart of accounts), Customer Contact List, Vendor Contact List, Product and Service List. Export each.
Invoices and bills
Sales, Invoices, filter all dates, export. Expenses, Bills, same. Or rely on the General Ledger which includes them.
Attachments
Settings (gear), Attachments, select and download. Tedious for large sets; do it in batches.
Then what
Keep the exports in a folder named for the year. Upload the bank transaction CSVs, or better, the original bank statements, to ProfitBooks and the AI rebuilds categorized books.