1. First of all, it is ok to apply for an extension, but there must be sufficient reasons.
Secondly, when applying for an extension, the author can write an email.
Finally, as long as the reason is reasonable, the magazine will consider it.
4. It should be noted that SCI papers are published through the system, and some system settings are established. If the author fails to submit the repaired article on time.
Some systems will automatically clear the modification status, which has a great influence on the author. So if the author needs to postpone, he must communicate with the magazine as soon as possible and let the magazine modify the submission status of the system.