Best not to get random, im betting many flowers in your plant shop dont grow naturally in the lizards wild habitat.
The Following flowers Are safe: Hisbiscus (Flowers/leaves) Dandeline (flowers/greens)
Rose (flower/ petals)
*Note: listed safe parts only, some parts of plants are toxic while others are sometimes not.
The above dont grow in my chams habitat either mind you, but Hibiscus is tried and trusted.
My veiled chams eat the above flowers, as do our beardys and various skinks.
Be aware live blooming flowers may not bloom as long as they do outdoors before wilting due to heating/lighting in the cage. Hibiscus a few days tops.
Occasionally the chams have a munch but mine are not huge plant munchers.