What is the meaning of Be_supposed_to?

Expected to.

1. Required to, obliged to, ought to.

   Required to, obliged to, ought to.

   Permitted to.

   Able to, capable of (used to indicate that an expectation is impossible or unreasonable in the context).

   Believed to; generally considered to; considered likely to.

   Intended to; meant to.

   Used other than figuratively or idiomatically: see supposed,‎ to.

   Source: wiktionary.org