Put background color (yellow) to the text on my shopify store.

Hi,

I need help putting yellow background to the text on my shopify store.

Right now, the text on my store is like this - https://i.ibb.co/fnVsP8m/1.png

I want it to look like this - https://i.ibb.co/tMhBz2g/2.png

With curved corners as well.

Please tell me what html code I need to use around the text, if I couldn't do it, then please do for me and teach me so I can do myself for my future stores.

Simple 5 min job.

Budget: $5 - $10

Thanks.