Do you have a desktop lamp? LED anything light? I have jars in a room with normal daylight, on a semi-dark bookshelf. If I want to look at them I have the following lights, check them out:

I got a bunch of these usb display lights, some jars get only light from this, including my moss garden, they love it. It's a bit yellowish: https://www.amazon.com/Display-LETS-RESIN-Lighted-Crystal/dp/B07T6ZS2XZ/ref=sr_1_11?crid=3KHIFET0W7WB4&keywords=small+LED+display+lights&qid=1649285031&s=home-garden&sprefix=small+led+display+lights%2Cgarden%2C129&sr=1-11

This is a little clip on light which is also perfect to put directly on the jar. It has white light: https://www.amazon.com/gp/product/B092H8PSQM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Or you can go full spectrum (which I would recommend only for land-jars), but this one here has only pink and blue light...make sure you get one with white light: https://www.amazon.com/gp/product/B087NL4FHX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

This is just to give you an idea what kind of light is sufficient. In other words, don't worry about not enough, only about too much.

To answer your question if the evening sun is too much...I have a jar that gets less than half an hour sunlight on about an inch of the jar...and that one inch is brown and green and impossible to see through the glass. That's all I needed to know :).