The idiom 'to blow one’s own trumpet' is used to describe the act of boasting or praising oneself, often in an excessive or exaggerated manner.
It implies that a person is highlighting their own achievements, abilities, or qualities, usually to gain admiration or recognition.
This phrase originates from the historical practice of a trumpeter announcing the arrival of a dignitary by playing a fanfare. By extension, someone 'blowing their own trumpet' is announcing their own importance or accomplishments.