Use one domain and three separate HTML pages. Each page tests one pain point, then sends shoppers to Amazon with its own Amazon Attribution link.

Replace AMAZON_ATTRIBUTION_LINK_TRAVEL / MULTIKEY / EDC with three separate Amazon Attribution links.
Insert GA4, Microsoft Clarity, Meta Pixel, or TikTok Pixel in the head section of each page.
Send comparable traffic to each page and compare Amazon DPV, add-to-cart, and purchases.