How to set shadow background to all float text packet?

How can I set in my AddPlayer package the black background color of the first text for all of them? I use this in the package:

PHP:

$pk->username = "BackGShadow \n NoBackGShadow ;-;";


If I use \n space, the background shadow is no longer implemented to the rest. Is it possible to configure all the text in this background shadow?

 

It's a Minecraft: Bedrock thing.

 

No, this was implemented long ago

 

No, it's a client-side thing. The shadow never goes for more than one line. I think you're thinking of Minecraft: Java Edition.

 

No, but i have already seen in all text's in mcpe, for example look the AvengeTech server!!

 

That's not one floating text, it's multiple. So again, Minecraft: Bedrock thing.