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.