// Class that I want to supply
public class User{
    public int? Name {get;set;}
    public DateTime? Bday {get;set;}
}

// My Controller
public async Task<IActionResult> GetUsers([FromBody] User user){
    // Do something here
}

// My js file axios is already imported and working
async searchUser(){
    const user = {
        Name: name,
        Bday: bday
    }

    await axios.get(`/SomePage/GetUsers/`,user).then(response=>{
        // do something here
    }.catch(error=>{console.log(error);});
}