Secondary CTA should be less noticeable
The goal of a CTA is to draw attention to the most wanted action on a page. When there are at least two CTAs, users are no longer being directed to the single most important action. Instead, it becomes their duty to mentally process each CTA and try to evaluate differences between them.
The most important action should always be the most prominent. However, this doesn’t mean that a secondary CTA must be avoided at all costs. Instead, a secondary CTA should also be second in the visual hierarchy. The goal is to naturally direct users to actions and areas of importance without imposing a cognitive load on them.