Do you apply sunscreen even on cloudy days and indoors?

I mainly work indoors all day until sunset. So, I often skip applying sunscreen. Can I get melasma and freckles even under artificial lighting?

I've heard that brightly lit places cause skin to tan. Just as freckles form from sunlight with high UV rays, does the same happen under artificial lighting?

If I get more wrinkles and age spots even under lighting, I'm thinking of applying sunscreen more thoroughly. But would they really appear under lighting?