how to add parameter in gql query

I would like to add parameter in gql query :

 onSubmit() {
    console.log(this.contact);

    let SendEmailQuery = gql`
    { 
      sendemail(contactorFirstname:"",
                contactorLastname:"",
                contactorEmail:"",
                contacteeFirstname:"firstname",
                contacteeLastname:"",
                contacteeEmail:"") 

    }
    `;

    this.apollo.watchQuery({ query: SendEmailQuery 
}).valueChanges.subscribe(({data, loading}) => {

      this.data = data;
      this.loading = loading;
    });

rather to add "firstname" hardcoded, I would like to pass a parameter ? anyone have an idea how to do it ?

thank you for your feedback,

best regards,

Nicolas Maujean

You can use an interpolated expression to pass a parameter in your query:

contacteeFirstname: "${firstname}"