Now that time for TPS re-registration is near;

could someone who is knowledgeable enlighten us

- what documents we need to re-register; do we need all as before, anything else, anything less?

It might be a good idea to get them ready in case something else is needed

Does someone know if it can be filed online; this would be awesome as it would be super fast and less cumbersome.

Let's hope for the best...

Go to other countries tps renewal application portal in USCIS you will get all your answers.

The following documents are required.
1) Form I-821
2) I-765 if you are applying EAD
3) I-94
4) Copy of last EAD and TPS approval Notices
5) Supporting Evidences
6) Fees(EAD + TPS)

What supporting evidences do we need for re-registration ?

If you are filing for late re-registration like I did, just submit what NepaliNajar posted along with a letter explaining why you are filing late. Copied from uscis website.
“If you are filing a late re-registration application, you must provide a letter explaining all of your reasons for filing outside of the re-registration period. If you are filing after the re-registration period because of the DHS announcement of the termination of TPS for your country, please explain how that announcement affected you, including how the termination decisions impacted your failure to re-register. However, if the announcement of the TPS termination did not cause you to file late, you should not include it as a reason. Please remember to be truthful in explaining your reasons.”

Thanks for all your help. NO IT IS NOT late registration, its for the regular re-registration for updated ead, ap and tps approval for Dec 2022.

One more question, are we allowed to pay tps fees with credit card, is there any reason we should avoid using credit card to pay for tps fees ? 

Trumps terminated TPS and was challenged in the court. Though ninth circuit court ruled in favor of trump and said termination of TPS was legal, it was appealed. The appellate court has not decided it yet. Finally it will reach Supreme Court for final decision. Because it’s still pending in appellate court, USCIS auto extended all tps related documents of a tps beneficiary. So tps for Nepal is different from regular tps for countries like Syria. Practically its same though.
U can apply for EAD and AP, but they will not issue you a tps approval letter with dec31, 2022 date if u apply for one. But the last approval letter is still valid though the date printed on it is out dated. Federal registrar notice over writes the outdated date on your last approval letter.

https://www.uscis.gov/humanitarian/temporary-protected-status/temporary-protected-status-designated-country-nepal

If you apply for EAD, AP and tps re registration, u will lose time, a month or two. Because they will not accept re registration, they will also reject ur EAD and AP. USCIS will reject/return or put in hold ur application if the check u sent for the fees is not exact. Not sure if you can send seperate checks for ead, AP and tps, if U really want to take a chance. If you send single check for all three, most probably it will be returned.
Only people who can apply for tps approval too are those who are applying for first time, it late registration

info about credit card payment

If you file one of the following forms with a USCIS Lockbox facility, you may pay with a credit card using Form G-1450, Authorization for Credit Card Transactions.

https://citizenpath.com/form-g-1450-credit-card-payment/#:~:text=USCIS%20will%20not%20charge%20you%20additional%20fee%20for,exactly%20$100.%20It%20is%20a%20one-time%20use%20form.

What forms can be paid with credit cards

https://www.uscis.gov/forms/filing-fees/forms-processed-at-uscis-lockbox-facilities