How to get specific fields only using formula?

[awesome1128]

How are you?
I love to use your library.
I use the getContent and getResponse functions to get fields.
Normally, airtable returns all fields from a table, but I don't want to get all fields because I don't need all fields and if I get all fields, there might be a speed problem.
I hope you understand what I said.
Please let me know, thank you!