Deadline/details for November GCSE Maths exams

I'm trying to self-study the GCSE Maths exam and sit it as an external candidate but couldn't find anything online about entry deadlines for the Nov series of exams. Also does anyone know how exactly I'd go about finding places that will let me sit the exams as an external candidate? Do schools usually hold regular exams for the autumn series, and if not, where else am I likely to be able to take the exams?

Thanks in advance, would really appreciate some help as I'm in over my head and feel like I might have left it a bit late

https://www.tes.com/magazine/analysis/secondary/gcse-resits-everything-you-need-know

School deadlines will be earlier - which board?

I was planning to do Edexcel as I have experience with it, but doesn't which one I can do depend on what the schools/centres can support?

You can search here: https://qualifications.pearson.com/en/support/support-topics/understanding-our-qualifications/where-can-i-take-edexcel-exams.html

Thank you. After using the tool it seems like my closest centre for Edexcel is some way away, do you know if this is an exhaustive list? What are the chances of one of the local schools allowing me to do Edexcel as a private candidate if I rang them up?

And to confirm based on your TES link, do I need to apply to the exam board before the 4th October or is that something the centre usually handles?

The centre's deadline will be earlier than 4th October and they make the entry. Could you ring your old school if that is nearby?

Suppose I should probably try and sort it as soon as possible then. I was homeschooled so don't have a school, and the college I went to doesn't do external candidates. Might have to just ring around local schools and pray for the best.

I would go on the school website - there should be info about the exam boards they offer. If they use Edexcel for GCSE maths they are more likely to help