NpgSql - How to call a stored procedure (void function) from EF core - asynchronously

I think there are a couple of questions embedded in here.

First, all documentation on calling a function from EF core seems to assume I'm waiting for a result set. E.g.:

_context.Set<MyEntity>().FromSql<MyEntity>("select myDbFunction({0})", myParam);

However, I have a background job I want to run after inserting or updating certain entities (it catalogs some json for faster searching).

This is the approach I was planning to take, or something like it:

    private void AsyncQueryCallback(Task QueryTask)
    {
        if (QueryTask.Exception != null)
        {
            System.Diagnostics.Debug.WriteLine(QueryTask.Exception.ToString());
        }
    }

    public void UpdateAccessionAttributes(int AccessionId)
    {
        var cancelToken = new System.Threading.CancellationToken();
        var idParam = new Npgsql.NpgsqlParameter("accessionId", NpgsqlTypes.NpgsqlDbType.Integer);
        idParam.Value = AccessionId;

        _context.Database.ExecuteSqlCommandAsync("generate_accession_attributes @accessionId", cancelToken, new[] { idParam }).ContinueWith(AsyncQueryCallback);

    }

But, of course, Postgres doesn't support named parameters, etc.

I'm also fumbling a bit on error handling. I don't want/need to await - just need a callback function to log any errors...

Help appreciated, as always!