Hi @Siriluck Tong-eim ,
The Send an email notification (v3) will send the email from Microsoft PowerApps and Flow. It can only send 100 emails every 24 hours.
The Send an email (v2) will send the email from you as the creator of the flow. It can send 900 emails every 60 seconds.
If you need more quota for sending messages, the workaround would be to use Send an email (V2) action from Office 365 Outlook connector. Per my knowledge, there is no other OOTB way.
Reference: https://learn.microsoft.com/en-us/connectors/sendmail/#send-an-email-notification-(v3)
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