How to convert an Estimate into an Invoice. Convert to Invoice option under ACTION not seen as stated in tutorial?

Allow me to help you convert an Estimate to an Invoice, Andrew.

To have the "Convert to invoice" option under the Action column, we'll have to change the status of your estimate first. You can refer to the screenshot below: 

Click Accepted, then enter the Date when your customer has accepted the Estimate.

Once you've changed its status, you should have the option "Convert to invoice."

On the other hand, if you want to create an Invoice directly without changing its status, please refer to the screenshot below: 

Once done, you can check out this article to learn how to run different kinds of reports:

• Reports included in your QuickBooks Online subscription
• Run reports in QuickBooks Online

I'll be around if you have further concerns about converting an estimate to an invoice. Keep safe.