Some time after installing extension, it does not appear in your store, to solve this issue we have to check few things that is given below:

Check list of extension installed in your store, you can do this by following command in your terminal.

sudo php bin/magento module:status

You will get list of all extension check if your extension exists or not, if not then type another command to enable your extension.

sudo php bin/magento module:enable YourExtentionName

Once done, you will get to see your extension on store.