Microsoft Lumia 640 XL

Find "Internet sharing"

Slide your finger down the display starting from the top edge of your phone.
Press ALL SETTINGS.

Find "Internet sharing"

Press Internet sharing.

Select settings for Wi-Fi hotspot

Press the edit icon.

Select settings for Wi-Fi hotspot

Press the field below "Broadcast name" and key in the required name for the Wi-Fi hotspot.

Select settings for Wi-Fi hotspot

If you want to password protect your hotspot:
Press the field below "Password (minimum 8 characters)" and key in the required password.

Select settings for Wi-Fi hotspot

Press the confirm icon.

Turn on Wi-Fi hotspot

Press the indicator next to "Sharing" to turn on the function.

Establish connection

Do the following on the device which is to connect to your Wi-Fi hotspot:
Turn on Wi-Fi.
Find the list of available Wi-Fi networks.
Select the network name you keyed in in step 2.
Key in the password you selected in step 2 and establish the connection to the Wi-Fi hotspot.
When the connection is established, you can access the internet from the other device.

Return to the home screen

Press the home icon to return to the home screen.