Technically, you can't fully replace X Ads’ native pixel with custom JavaScript tags alone for official conversion tracking, attribution, or campaign optimization. Here's why:
Why the Native X (Twitter) Pixel Matters:
The X Ads pixel is what ties on-site activity back to your ads and enables conversion tracking, optimization, and attribution inside the platform.
Custom JavaScript tags (like from GTM or your own scripts) can fire events, but they won't be recognized by X Ads unless they’re linked to the X pixel or Conversion API.
What You Can Do with Custom JavaScript:
You can also use Google Tag Manager to fire these events conditionally based on button clicks, page visits, or other triggers.
However, these still rely on the X pixel being properly installed—you're just using custom logic to decide when to trigger it.
What You Can't Do:
You can’t just send event data to X Ads using arbitrary custom tags (like custom endpoints, server-side posts, or non-X methods) and expect it to be tracked.
X Ads doesn't currently support a full Conversion API like Meta does, so server-side-only tracking isn’t an option (as of now).
Bottom Line:
You can customize how and when events fire using JavaScript, but the events must be fired via the twq() function tied to the native X pixel. There's no workaround for official conversion tracking without it.