Handle binary data at backend using golang - go

Question

I don't even know if i had asked the right question or not, but here it go anw.
The question is which data type in golang i should use to store binary data
In the front end i using vuejs and sending a file with axios post request using formData as request body.
1 field in this body is a file which if i check in the devtool it show as (binary) like this : enter image description here
and if i console log it's type then it show as an object
In the front end i send the request :
CreateAccount(){
var formData = new FormData();
formData.append('cv',this.cv);
axios({
method : 'post',
url : 'http://localhost:1323/restricted/Profile',
headers: {
'Authorization' : 'Bearer ' + this.$store.state.token,
'Content-Type': `multipart/form-data;`,
},
data : formData})
In the backend with golang, i use []byte to store this data like this :
Cv []byte `json:"cv" form:"cv" query:"cv"`
But this field return as an empty array, maybe there is a missmatch data type in here so they just don't store my data ?? please help. I have struggle with this 1 task(sending a file in the front end and receive that file in the backend, store it in the postgre db) for more than 3 days
Ther are actually no error. It just that mine Cv varible in the backend return empty, there are nothing in it whereas the other field had the correct value