Combining arrays from dictionary in Javascript

I have the following structure:

ley objects = {
   key1: [1, 2, 3],
   key2: [3,4,6],
   key3: [5, 6, 7],
}

How can I combine those arrays keeping any duplicates so I will have [1, 2, 3, 3, 4, 6, 6, 6, 7]? I have tried concat but I cannot seem to find a way to do so. I have many more keys so it has to be some loop:

My attempt so far:

let arr = []
for(const [key, value] of Object.entries(objects)){ 
    arr.concat(value);
}

Would there be a possible way to avoid this loop?

Answer

You could flat the values from the array.

let object = { key1: [1, 2, 3], key2: [3, 4, 6], key3: [5, 6, 7] },
    result = Object.values(object).flat();

console.log(result);