Go back to their answers under your original question in the forum. Click the thumbs-up symbol at the bottom left of each answer to thank them. You can also click the three dots at the top right of an answer, then click "Mark as Best Answer" on the pop-up menu. There can be more than one best answer.
Here's a link to your question about estimated tax payments, with the two answers below it.
https://ttlc.intuit.com/community/taxes/discussion/do-my-four-estimated-tax-payments-for-the-year-al...
