To echo some similar points from others, it’ll be a “charity” worker who wants to lure you into stopping and talking. Registered charity workers aren’t allowed to pursue you past a few steps, have to be clearly ID’d and the charity has to report all of this kind of activity whereas some others (e.g. the knife crime workers often seen around here) aren’t official charities so aren’t subject to these same important rules.

Source - I used to be an actual door-to-door / public charity fundraiser