In the past I recommended Coppermine but Coppermine broke with 7.2. It really died do to lack of interest and maintenance. The authors did not keep it up to date with modern PHP standards.
I recently replaced my Coppermine Gallery with Piwigo. Piwigo is MUCH more capable, it has a plugin extension method and there are around 300 plugins currently available. It works fast and proper with our hosting facilities.
You can get it here: https://piwigo.org/get-piwigo
If you do not have a database setup yet, you will need one so in that case e-mail support@eskimo.com and request a database. There is no charge for this.
If you’d like to see how this looks, you can visit my gallery at: https://www.eskimo.com/~nanook
If you need any help e-mail nanook@yellow-snow.net or support@eskimo.com