TypeScript Error: 'Promise<NavProps | null>' is not assignable to type 'null'

This error message indicates that a value of type 'Promise<NavProps | null>' cannot be assigned to a variable or parameter of type 'null'. This is because a 'Promise<NavProps | null>' is an object representing a value that may or may not be available in the future, while 'null' is a primitive value representing the absence of a value.

To fix this error, change the type of the variable or parameter to 'Promise<NavProps | null>'. Alternatively, change the type of the value being assigned to 'null' if it is not actually null.