How to rewrite or set sensitive header with got dependency

i’m working with internal library that wrapping got dependencies. and when i try to insert or request some data to 3rd api with this headers:

'Content-Type': 'application/json'
'X-Reference-Id': payload.accountNo
'X-Api-Key': 'example'
'X-Id': 'example'

got plugin convert the headers to lowercase like this:

'x-reference-id': payload.accountNo
'x-api-key': 'example'
'x-id': 'example'

and this is caused error to my request because headers for 3rd api is case sensitive.

can i rewrite or keep the headers in default form to avoid this? i can’t move to another dependency like axios or native method fetch (using those dependency solving my problem). but it’s not allowed because we are using internal and embedded library for our service.
please give me advice, thank you.