https://qboe.custhelp.com/app/answers/detail/a_id/2538/kw/align%20checks/r_id/103898

Alignment instructions for Checks or Check Voucher

Note: We can only guarantee compatibility with checks specifically designed for QuickBooks Online.

Go to the Banking tab, then the More dropdown menu and click Print Checks.
On the right click on Set Alignment [+] to open the […]

Resolution for 'align issue: 'How do I align checks?' available: Yes.

The align issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the align issue yourself by looking for a resolution described in the article. If it is a complex align issue or you are unable to solve the issue, you may contact us by clicking here or by using other align support options.

For more information about resolving issues related to align in Quickbooks/QBO or to get support for the issue 'How do I align checks?', click the link below: