The Plugin AWS4 who was created by Br4uN_Tr 
PICTURE (Br4uN_Tr Post)
Can generate only the signing_key not the signature token (But a part of creating signature)
PICTURE
but to generate signature you need this signin_key and string to sign
This is how to generate the right signature token
now i have the ‘signin_key’ and ‘string to sign’ those variables but i dont know how to generate them
using HMAC and HexEncode like in the pictuer. if Br4uN_Tr can help or any one.
If you Have both keys, Just encode it. Simple !!