how to convert HCL2 into json?

hello!
I used function `unmarshal` to convert HCL into `interface{}`, but I meet the error of "unknown token : data xxx xxx". I think it is the problem of HCL version.
But I can not find the way to convert HCL2 into json. It seems `hcldec` cmd can do the work, but I cannot find the function which can do the same thing.

Start by comparing the hcldec command with the unmarshal function mentioned in the issue, focusing on how HCL2 input is represented and converted. Check whether an existing API provides equivalent JSON conversion; done means documenting the supported approach or clearly identifying the missing capability.

Written by the indexing model from the issue text.