Android Question Embedded printer

Olle Marcelo.
Hay varias librerias blue T en el foro, Yo uso algo parecido y fijate que el algunas ocaciones tambien permien BT, de no ser asi nececitas el SDK para ver por que puerto trabaja y su configuracion .

Otras Trabajan con ID vendor y Id Product que poldria servirte ajustando algunas lineas de codigo simples.
Cualquier cosa podriamos buscar una solicion.
Suerte

Can you post the dsk (jar) file and manual here?

In this git: https://github.com/gertecdeveloper/GS300/tree/main/Android_Nativo_Java/Projeto GS300 novo
There are JARs and an example of their use in Java.
Here: https://www.gertec.com.br/produtos/gs300-smart-pdv/ is the product manufacturer's page.
In the first post I put the URL for the TSG810, this git is for the GS300. Both are from GERTEC, the TSG810 is a mobile POS. The GS300 is a tabletop POS, it has more features than the other mobile device, such as a QR-code reader, two screens, USB and serial ports for connections to scales.
I need to develop for both. And any help I would be very grateful.

Thank you all in advance for your feedback