You'll need to look in the bounty threads, found in the Services sections of this forum (Bitcoin and alternate cryptocurrencies). But if you're really a charity with serious aims and clear objectives, why not apply for funding from the UK government or one of the many other charity funds online? I might mention that you could complicate your funding reportings as a registered charity in the UK if you start generating income from crypto.
If this is not a problem, and you're still keen on applying for charity funding with a good proposal including a clear budgetline for expenditure, take a look at Pineapple Fund:
https://pineapplefund.org They've still got more than $60m of Bitcoin to give away to charities.