Blow it
(PW) lose a chance, make a mistake
I knew I blew it when I forgot my lines in the play.
(freedictionay)
(informal) to spoil your chance of achieving something you want because of something you do or say
She was hoping for promotion but she blew it when she got pregnant. They want to publish his autobiography so let's hope he doesn't blow it by arguing with the publishers.
(slang) to lose an opportunity
Most people think Congress blew it on the environment by not acting quickly on the president's proposals.
Related vocabulary: throw away something
(yourdictionary) idiom
Spoil, botch, or bungle something, as in That was a great opportunity, but now I've blown it. [Slang; c. 1940]
blow one's lines. Make a mistake in speaking one's part in a theatrical production, as in Ben blew his lines, but Dean came to the rescue. [Mid-1900s]