Although the Bid, Labor, and Material Exports are available to any licensed user, the Accounting and Custom Exports are only available to users under a maintenance subscription.
If you've allowed your maintenance subscription to expire, you can renew easily by clicking File > Check Authorization and clicking the Renew link.
That link opens the MyOnCenter customer portal where you (or whoever can pay the invoice) may renew your maintenance subscription.
You can also contact Customer Success to discuss renewing your maintenance subscription.