This is the correct location. 
See location next to exit doors here: https://lh3.googleusercontent.com/p/AF1QipNk35JVqBXu-B1bjrvaTGpldjxpFEaUOGTuih3-=s1360-w1360-h1020

See map of Kings Square here: https://webcaps.sandwell.gov.uk/publicaccess/files/4A3191675D19B888D7959FD4990CB036/pdf/DC_17_61230-SITE_PLAN-921550.pdf

It appears that the source referred to in the note has the wrong address.