Solution 1: in view

                const age=48;
                return(
                  <button>{age > 18 ? "Watch Now" : "Not Available" }</button>
                )

            

Solution 2: using variable in componenet

                let canWatch="Not Available";
                if(age > 18 ) {
                   canWatch="Watch Now";
                }

                return(
                  <button>{canWatch}</button>
                )

           

Solution 3: using function in in componenet

                const canWatch =() => {
                    if(age >18){
                        return "Watch Now";
                    }
                    else{
                        return "Not Available";
                    }
                }

                return(
                  <button>{canWatch()}</button>
                )