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Remember to turn off you Admin Key before getting access token. You can turn on this Admin Key later after connecting Magento 2 to Zoho CRM successfully.
Go to Stores > Configuration > Advanced > Admin, choose No in Add Secret Key to URLs.
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Click Save Configuration then Get Access Token in Zoho CRM Configuration.
You will be redirected to Zoho, in here Zoho will require to access your information. Click Accept
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