There are several ways to change locale, you can try all of them to find what works for you,

Use Args when launching

const browser = await puppeteer.launch({

    headless: false,

    args: ['--lang=bn-BD,bn']

});

Send the language as Header

await page.setExtraHTTPHeaders({

    'Accept-Language': 'bn'

});

Forcefully set the language

// Set the language forcefully on javascript

await page.evaluateOnNewDocument(() => {

    Object.defineProperty(navigator, "language", {

        get: function() {

            return "bn-BD";

        }

    });

    Object.defineProperty(navigator, "languages", {

        get: function() {

            return ["bn-BD", "bn"];

        }

    });

});

For the sake of testing, I'll test this in multiple languages, including es, and here is the result.

Google search:

BrowserLeaks: