@flash1293 you are right...
Anyway, the main problem I asked in this topic is solved 
From the puppeteer side, using the code below I got the same result
that I wanted:
await page.addStyleTag({
content: ".euiHeader{display: none};",
});
await page.addStyleTag({
content: ".euiNavDrawer{display: none};",
});
await page.addStyleTag({
content:
".chrHeaderWrapper ~ .app-wrapper:not(.hidden-chrome){top: 0px};",
});
Thanks again to everyone