The products are gone after changing the search engine. What should I do?

After installing the Elastic Search, reindex is required.

To perform the reindex, please use the following command:

php bin/magento indexer:reindex

After the reindexing is finished, please clear the page cache for changes to become visible on the frontend.

To refresh the cache using the Admin backend panel, log in and navigate to:

• System > Cache Management.
• Select the checkbox next to Page Cache.
• From the Actions list in the upper right, click Refresh.