Each note can hold a Mobile Number and an Email Address, under Contact Information in the note form. Then you can call, text or e-mail straight from the note.
Choosing from your contacts: tap the contact icon (Choose from contacts) next to the number field and pick a person and number. This uses the phone's own contact picker: 1krNote receives only the number you chose, needs no contacts permission and can't see your other contacts.
By voice: say the number to the AI assistant, or a name from your contacts ("remind me to call Mark Sutton"); see "Call Mark Sutton: the AI and your contacts".
Numbers and e-mails stay in the note on your phone and aren't sent anywhere.