Please note, the receipt you have received is an official tax receipt issued by everydayhero on behalf of your charity and is a legal receipt.
There is not anything more you need to do to gain a tax receipt.
However, whether the receipt is tax deductible is entirely dependant on the school/ charity itself. The charity needs to have tax deductibility, which only certain organisations are entitled to, in order for any receipt issued on their behalf to be tax deductible. If your receipt is not tax deductible, it will explicitly say it on the donation receipt for your reference.
My best suggestion here would be to contact your charity to enquire further about their DGR status.
Thank you for using everydayhero to support the cause you care about and if you have any other questions please feel free to let us know.