How can i specify in TurboTax to send my refund as a check to the embassy

No. The IRS can only send your refund check to your personal address listed on your tax return (on the first page of your form 1040).

I live overseas in Asia, will they send the check to my home. As per my understanding, in some countries the embassy is receiving stimulus checks.

Is it a different thing between stimulus and tax returns?

The IRS is using the same database for refunds and stimulus payments.

If you do not have a U.S. account, or do not choose to receive your refund via direct deposit, a check will be mailed to the address you provided on your tax return.

Please read this IRS document for more information.