API call for a field of type number

Hi
I'm trying to make an AIRTABLE API call
To update a record
The field I want to update is a field of type number
And when I try to enter a number I get this message
Field "Hours used" cannot accept the provided value
Of course I enter only a number without signs
This is the body of the API call I'm making

{
"fields": {
"Hours used": "35"
}
}

I will rejoice in repentance
Thank you