The way to ENSURE you are taken into custody is to ask if you're being arrested under a section 50 stop and search order and then say I'm being entirely peaceful but I will not give you my name or address

That is perfectly legal

Then SAY NOTHING TO THE POLICE !
https://news.sky.com/story/palestine-action-supporters-urged-to-demand-they-are-taken-into-custody-if-they-are-arrested-13424360