A possibility: https://idea.org.uk/
This is not a pure computing idea but there are elements that should be suitable. Some of the badges are about websites, micro:bit, Python, gaming, cyber security, etc.
iDEA is an international programme that helps you develop digital, enterprise and employability skills for free. Through our series of online challenges, you can win career-enhancing badges, unlock new opportunities and, ultimately, gain industry recognised awards that help you stand out from the crowd.
Wigan council video: https://www.youtube.com/watch?v=Tc1MmhKvigA
Basically, it is free, for anyone of any age, and is completely online. Some primary pupils have done the Bronze level. Gain 250 points to receive the award from Buckingham Palace. Like DofE it has three levels: Bronze, Silver, and Gold (in 2019). Points are achieved by completing the learning challanges (digital badges). They range from 2 to 20 points at Bronze level, with 2 points taking the least time. Badges booklet:
The learners choose the badges that they want to do in the order that they want to do them. They must complete a badge in one session, which isn’t time limited. Not all of the badges must be completed, only enough to get 250 points.
Some tips if signing up:
1. Get pupils to sign up using Glow email address as this is useful for password recovery.
2. Password – minimum 8 characters. Must contain a number and a symbol.
3. If 13 or under they will need a parent/guardian email address. For the parent/guardian name I just get them to put mum or dad – reduces the personal info that is handed out.
When they achieve 250 points they will receive an email with a link. At this point they will need to give some personal information: their name and address. The award will then be sent to them.
I hope this helps.