postal id is one of the primary id in the philippines because we dont have national id and uphold says they dont accept it.
You do or will soon have access to a national ID as a result of the Philippine Identification System Act. It will be free to obtain. If you receive benefits under the Unconditional Cash Transfer program you can apply for one already. If you do not you will be able to apply in a few months.
However, you’re making a big deal out the term “national ID” for nothing. You already have the ability to obtain a driver’s license license for about 821 pesos which Uphold will almost certainly accept.