how can i handle the option value?

[kulame]

my query function

pub async fetch(pool:&Pool<Postgres>,tag_id:Option<i32>){
    let a = sqlx::query!(
        r#"
            select * from articles where $1 is null or $1=any(tags)
        "#,
        tag_id
    ).fetch_all(pool).await?;
}

the error msg is "could not determine data type of parameter $1"
how can I do this query by sqlx?