I still carry a গামছা in my shoulder bag, which I purchased in the early days of the pandemic for this special purpose.
Whenever I face a situation where I HAVE to wear a mask otherwise they won't let me in, I take it out from my bag and twist it around my face. Done. The guards can't object to anything.
And mask rules show that someone was forced to do something and therefore he came up with this impractical rule as a ritual.
As when inside a Bank, you are specifically told through wall notice to take off the mask for CCCam compliance and identification for security.
So much for "have to wear a mask at gate" rule.