// Add to lib file (example ab-design.at)
lib.currentPageId = TEXT
lib.currentPageId.data = TSFE:id
<f:if condition="{f:cObject(typoscriptObjectPath:'lib.currentPageId')} == 55">
<f:then>
// something
</f:then> <f:else>
// something
</f:else>
</f:if>
https://stackoverflow.com/questions/40088721/check-if-pid-of-current-page-is-x