Here’s the exercise in simple terms…

Play a note…. listen relaxed with “big ears”… let the sound of that note wash over you…

let the note die naturally and as it does try to keep that note going in your head…

Keep that note in your head as you play the same string one fret lower… SLOWLY bend that string up to match the note you kept  in your head…

take your time and keep adjusting until you are happy… as this bent string dies keep the note in your head… play the original fretted note you played first to check how well you did.

Repeat this for 2 minutes a day for a month and your playing will drastically improve,