Breakdown of ryoukinpuran o kakuninsuru.

Questions & Answers about ryoukinpuran o kakuninsuru.
を marks the direct object of the verb. In this sentence, 料金プラン is the thing being checked or confirmed, so it takes を.
- 料金プランを確認する
- Check/confirm the pricing plan
A very literal breakdown is:
- 料金プラン = pricing plan / fee plan
- を = object marker
- 確認する = to check / to confirm
So を shows that 料金プラン is what the action is being done to.
料金プラン is a compound noun made of:
- 料金 = fee, charge, rate
- プラン = plan
Together, 料金プラン means something like pricing plan, rate plan, or subscription plan, depending on context.
This kind of noun + noun combination is very common in Japanese. The first noun modifies the second:
- 料金プラン = a plan related to fees/pricing
- similar idea: 旅行プラン = travel plan
So the whole phrase is just one noun unit.