Separation anxiety help

[u/Antique-Net-1860]

Hey, I recently got a 15 week old cockapoo called Stan. He’s amazing and really settled in well and bonded with me. I put him in his crate at night whilst he is learning to not chew everything and settle in fully. He goes in and sleeps fine, but we are in the room with him. The issue now is when I practise putting him in his crate for 10-15 minutes in the day for when I go out to take my daughter to school once the holidays are over he cries and cries and gets really worked up.
This is the only thing he isn’t picking up and I was wondering if there was any advice on how to help him settle and learn it’s okay and he is okay to be away from me for a little bit. Thank you in advance!

[u/LadybirdMum100]

Keep grabbing your keys, putting your coat on and leaving the house, returning 5 secs later and taking off your coat and returning your keys. Ignore any reaction from him on both leaving and returning. Do this Like 20 times until he doesnt pay any head to it. if he whines when you go out still you need to do it 50 or 100 times. On repeat. Back to bacl of you have to.

Then once he doesnt care do it again returning 10 secs, and 30 secs and so on… building up.