Always keep in mind that some CBD products, as well as other hemp products and THCA flowers, contain THC. As long as the content is below 0.3%, they can be legally sold online. The legality of THCA can be somewhat complicated because it can vary from state to state. Even though THCA doesn't have the same psychoactive properties associated with THC, it's still considered part of the cannabis plant (and converts to THC when exposed to heat).
Therefore, many local and state laws regulate THCA in the same way as they do with cannabis. In some states, it may be legal to shop at licensed dispensaries, while in others there may not yet be official laws governing it.