> For the complete documentation index, see [llms.txt](https://docs.magecomp.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.magecomp.com/magento-2-cash-on-delivery-verification-extension/sms-gateway-api-settings.md).

# SMS Gateway API Settings

To verify customer mobile numbers for using the COD payment method, we have integrated the extension with 3 different API Gateways to send OTP messages.

<figure><img src="/files/1DPnBlNi312BBmrtxMvQ" alt=""><figcaption></figcaption></figure>

* **SMS Gateway:** You can select your preferred SMS Gateway from the dropdown option.
* **OTP String Type:** Select the string type you want to use, either Numeric or Alphanumeric.
* **OTP String Length:** Select your OTP String length between 1 to 10.

**Bulk SMS:** By selecting “Bulk SMS” as Gateway, you need to enter the following details to send OTP texts.

<figure><img src="/files/NM4Ko4pggAJyUHEngYpf" alt=""><figcaption></figcaption></figure>

**MSG91:** By selecting “MSG91” as Gateway, you need to enter the following details to send OTP texts.

<figure><img src="/files/UJzt1E4tQS091JToCpw2" alt=""><figcaption></figcaption></figure>

**Twilio:** By selecting “Twilio” as Gateway, you need to enter the following details to send OTP texts.

<figure><img src="/files/gGU2TEY1OJf5mAhwZhgE" alt=""><figcaption></figcaption></figure>