Place {{ISBN missing|date=June 2024}} outside the citation template
Do not place it in the |isbn= parameter of a Citation Style 1 template. The inclusion of text other than the digits of an ISBN in |isbn= corrupts the citation's COinS metadata and the citation's link to Special:BookSources.
With a free-form reference, just append {{ISBN missing|date=June 2024}} to the end of the citation.
With either method or format, it will render a [ISBN missing] inline note.
How to fix the problem flagged by this template
Do not remove the {{ISBN missing}} template without fixing the problem in one of the following ways:
Determine the ISBN, add it to the reference, then remove the {{ISBN missing}} template
If you are certain that the source document does not have an ISBN, add a {{No ISBN}} template to the reference, then remove the {{ISBN missing}} template
1. Use its ISBN parameter to state explicitly that the ISBN does not exist:
|isbn=<!-- ISBN unspecified --> (you must use HTML<!-- -->comment tags to hide the message from the citation processing software)
2. Place {{No ISBN}} outside the citation template
For free-form reference, just add {{No ISBN}} to the end of the citation.
If you remove the {{ISBN missing}} template without fixing the problem in one of the above ways, someone else will come along later and flag the reference with {{ISBN missing}} again!
Do not place it in the 
