It would depend on your country's tax treaty and the treatment of the Roth 401k's annual required minimum distributions (RMDs). In comparison, for countries that don't accept Roth IRA pension income as tax free when tax resident in that country, the Roth IRA allows you to flexibility plan income amounts to stay under income thresholds for tax. This is one of the things you need to consider with a Roth 401k.

However, you could rollover funds from a Roth 401(k) to a Roth IRA, just be aware of the clock for the 5-year rule.

If doing any of this stuff please for the love of binary get proper financial advice!