@sat_miha, thanks for the clarification 
The Base64, Hash & HMAC Encryptor plugin can encrypt your API call value:
Design part:
https://prnt.sc/skfbz6
https://prnt.sc/skfc5y
https://prnt.sc/skfcj7
Workflow part:
https://prnt.sc/skfdts
https://prnt.sc/skfegi
https://prnt.sc/skffew
Test preview:
https://prnt.sc/skfh2m
https://plugindemo.bubbleapps.io/version-test/testch?debug_mode=true
But the value can’t be decrypted back (it is not possible to get back the original token).
You can try out other plugin - Encode/Decode/
Encrypt/Decrypt:
Hope this info will be helpful to you.
Regards,
Zeroqode Team