Is it possible to upload a file optionally?

[Genza999]

I have a mutation where I upload a file and other parameters too but this file can be omitted or included if need be. I am using graphene-file-upload for this, but when I try to omit the file from the request, I get the error.
In the operations section of my insomnia/postman, I remove the file variable:
from:
{ "query" : "mutation($file: Upload!, $name: String!){createPerson(file:$file, name: $name){success, errors}}", "variables" : { "file" : null, "name": "Kate", } }

to:
{ "query" : "mutation( $name: String!){createPerson(name: $name){success, errors}}", "variables" : { "name": "Kate", } }

The error:
{ "errors": [ { "message": "mutate() missing 1 required positional argument: 'file'", "locations": [ { "line": 1, "column": 61 } ], "path": [ "createPerson" ] } ], "data": { "createPerson": null } }
I guess since this file is included in the parameters of the mutate method.
Is there a way I could work around this? Thanks