To use services such as the BKNIX NTP server, RPKI server, without going through a transit provider, you should peer with BKNIX Services AS, 63528.
When you have made your arrangements with the BKNIX administrative process, you should have received credentials to access your account on the BKNIX IXP-Manager with your registered email. Here is the Documentation for IXP-Manager
For cryptographically secure resource validation, you should register in the Resource Public Key Infrastructure. You need to use the registry from which you acquired your address space; for Thai address holders, this is usually APNIC.