I have Minecraft on my PS4 and mobile device. Is there a way for me to share the world that is on my PS4 account to my mobile so I can play while I’m out and about?
The Bedrock edition of Minecraft, which allows for cross-play with other platforms, is not yet available on PS4. However, source code referencing the PS4 version of Bedrock edition has been discovered, so it is expected that a PS4 release is in development.
Until then, you will not be able to share worlds or cross-play between your PS4 and mobile devices.
As of December 2019, the PlayStation 4 version of the game received an update to enabled cross platform support, as this article states.
The official Minecraft.net store page for the PlayStation 4 version also states:
Cross-platform play for up to eight players across Windows PCs, Android devices, iOS phones and tablets, Xbox Series X|S and Xbox One, Nintendo Switch, PlayStation 4, and virtual reality platforms