I am doing integration of api that accept documents which must be signed with qualified signature, our software provider Szafir SDK E-signature Szafir / Offer / Programming tools provide us a testing certificate, but this testing certificate cannot have custom attributes like TAX number which is required by api we integrate with, even though it is testing environment we need TAX number to be included. The api require that signature follow ETSI EN 319 412-1 standards which require tax number or some identification number.
Our solution will run finally in the cloud maybe with cloud HSM but at the moment we only want to finalize integration with the api, one of the api endpoints is not working as our test cert doesn't contain TAX number.
My question is can we use let's encrypt to create a test signature, which will be used to signing documents ? We need PKCS#12 file that Szafir SDK is using.
Maybe somebody could point me to right direction ? We cannot use cert on yubikey or sth, as the system we build is working on the cloud.