Bianchigirll;

It is possible to run multiple front chainrings with an IGH. To do so a dual pulley chain tensioner needs to be fitted such as the Shimano one or a rear derailleur, permanently adjusted to align with the position of the IGH cog, can be used. I run a single ring as the range of the Shimano 8 speed hub is adequate for my riding. My low is about 32 gear inches and high about 100. I am running 48/21 gearing on 700c wheels.

With your front rings you need a chain tensioner that can handle 20 teeth of chain slack.

If I need a wider range I ride the Rohloff hub bike.