How can I unlock my sim carrier

The phone was locked by a Carrier when new and only that same carrier can unlock it - if they wish to.

Contact their help desk.

my iphone was carrier at a state i need to change a carrier a filipino simcard please help me

Doesn’t matter which SIM you want to put in it, its the carrier who locked it that you need to contact.

If you don’t know who they are it can be tough.

If this was a pre-owned purchase get the carrier name from the seller or get a refund.