Unlock washing machine door?

[nameisme]

Hi all

We have a

Indesit My Time EWD71453WUKN 7kg Washing Machine with 1400 rpm - White - D Rated​

However, when I pressed some buttons by mistake I think I may have activated the child lock. Now I can't turn it off or open the door.
I've unplugged it and left it for ages and pressed and held the on off button and the start button but nothing gets rid of it or open the washing machine door.

Any help appreciated alot.

 

[Old Salt]

Info on the web says make sure machine is empty but found this on you tube. Not sure if it will work for you