To use this in your tables, download, install, and activate this Extension like a regular WordPress plugin. Then change your table’s Shortcode from something like
[table id=123 /]
[table id=123 datatables_columnfilter="true" /]
Additionally, make sure that the “Table Foot” checkbox in the “Table Options” section on the table’s “Edit” screen is checked. You might have to add a new row to the table as well. The values in the cells in the last row are then used as the default text in the generated search input fields. Usually they should have the same content as the table head row cells.
If this Extension is helpful for you, please consider supporting further TablePress development with a donation. Thank you!