react admin newrecords.Forach n'est pas une fonction

The problem is due to your data sample format, in that case your API respose it is an object, but it need to be an array instead. Like this:

[
     { id: 126, title: "allo?", author_id: 12 },
     { id: 127, title: "bien le bonjour", author_id: 12 },
     { id: 124, title: "good day sunshine", author_id: 12 },
     { id: 123, title: "hello, world", author_id: 12 },
     { id: 125, title: "howdy partner", author_id: 12 }
]
GutoTrosla