Depending on your nationality, you will need a visa to come to the UK.
You can check if you need to apply for a visa here: https://www.gov.uk/check-uk-visa. For attending the conference, you should select “Work, academic visit or business” as your reason to come to the UK.
If you need to apply for a visa, you should apply for a “Standard Visitor visa”: https://www.gov.uk/standard-visitor/visit-on-business.
Please start preparing your visa application well in advance of your travel.
You can start your application process online here: https://www.gov.uk/standard-visitor/apply-standard-visitor-visa
As part of the online application, you need to book an appointment at a visa application center. You can find the locations of UK visa application centers on this website: https://www.gov.uk/find-a-visa-application-centre.
After you have applied online and completed your appointment at the visa application center, you should usually get a decision on your visa within 3 weeks.
Please contact the general chair if you have questions around the visa application process.