Firstly, you need to create group for mentions in the project you'd like to display on your widget - so you can have more control over what will be displayed over there :) You can do that following those steps.
The next thing, go to Account Settings and find Widget list option - click on it
And now we'll move to creating your widget :)
Firstly, choose a project that you want to share. Select the Order of Mentions: you can sort them by the most popular mentions OR the latest. Choose the Group of Mentions that you want to display
and we're on to the next step where you can select theme and colours - after setting those, please save changes
Now, all set up! You can copy the code to embed it on your website :)