Help! Multi-Window Missing

[Mdm23]

Since my update to pie, multiwindow seems to be missing, or I don't know how to activate it with this new update. Anybody else having this issue?

 

[mustang7757]

you have to go in recent apps then hold the icon it give option

Edit: also make sure Dolby atmos you checked on in drop down notifications panel it's off by default for better sound