Planning on purchasing 1 month of Mullvad with XMR. What does "use sufficient fees so the TX gets confirmed on time" mean?

<a target="_blank" href="This is the option for monero purchase:Pay with MoneroUse a one-time payment address to credit your account.Refunds are not supported when you pay with monero.Do not reuse a one-time payment address: your account will not be automatically credited.Processing the payment may take up to 30 minutes after it has been confirmed on the blockchain.The address is only valid for 3 days, don't save it for later.Use sufficient fees so the TX gets confirmed on time.We are unable to recover your account number if you lose it. Ensure you have it safely stored.I have my account number saved and I want to pay for it. I just don't know how to use "sufficient fees". I use a getmonero.org GUI.Anything else I should know before I make the purchase?" title="Planning on purchasing 1 month of Mullvad with XMR. What does "use sufficient fees so the TX gets confirmed on time" mean?">full image</a> <strong> - Repost: Planning on purchasing 1 month of Mullvad with XMR. What does "use sufficient fees so the TX gets confirmed on time" mean?</strong> (<i>from Reddit.com, Planning on purchasing 1 month of Mullvad with XMR. What does "use sufficient fees so the TX gets confirmed on time" mean?</i>) <br><blockquote> This is the option for monero purchase:Pay with MoneroUse a one-time payment address to credit your account.Refunds are not supported when you pay with monero.Do not reuse a one-time payment address: your account will not be automatically credited.Processing the payment may take up to 30 minutes after it has been confirmed on the blockchain.The address is only valid for 3 days, don't save it for later.Use sufficient fees so the TX gets confirmed on time.We are unable to recover your account number if you lose it. Ensure you have it safely stored.I have my account number saved and I want to pay for it. I just don't know how to use "sufficient fees". I use a getmonero.org GUI.Anything else I should know before I make the purchase? </blockquote> <hr><h3> <hr><strong>Mining:</strong> <br> <a title="Cryptotab browser" target="_blank" href="https://cryptotabbrowser.com/12/4000343"><u>Bitcoin</u>, Cryptotab browser</a> - <a title="Pi Network, CLOUD PHONEMINING" target="_blank" href="https://minepi.com/cusidore"><u>Pi Network</u> cloud PHONE MINING</a> <br><a title="Fone, CLOUD PHONE MINING" target="_blank" href="https://play.google.com/store/apps/details?id=com.cloud.earning"><u>Fone</u>, cloud PHONE MINING</a> cod. dhvd1dkx - <a title="Mintme, PC PHONE MINING" target="_blank" href="https://www.coinimp.com/invite/86d61388-18f9-4f8b-8561-8962c67e7166">Mintme, PC PHONE MINING</a> <hr><strong>Exchanges:</strong> <br> <a title="Coinbase.com" target="_blank" href="http://coinbase.com/join/occhip_8?src=android-link">Coinbase.com</a> - <a title="Stex.com" target="_blank" href="https://stex.com/?ref=27877494">Stex.com</a> - <a title="Probit.com" target="_blank" href="https://www.probit.com/r/46858290">Probit.com</a> <hr><strong>Donations:</strong> <br> <a title="Done crypto" target="_blank" href="https://commerce.coinbase.com/checkout/140e9bb6-c4ef-4156-92cf-9c87a88fd259">Done crypto</a> </h3><br><br>