Hey, I tried to  make it so all participants in my task would first all get the same practice block but then have a different order for the other blocks depending. Is this the accurate syntax for it ?
<expt>
/ subjects = (1 of 6)
/ groupassignment = groupnumber
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2 = wordmemory; 3 = wordmemory2; 4 = wordmemory3;]
</expt>

<expt>
/ subjects = (2 of 6)
/ groupassignment = groupnumber
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2 = wordmemory; 3 = wordmemory3; 4 = wordmemory2;]
</expt>

<expt>
/ subjects = (3 of 6)
/ groupassignment = groupnumber
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2 = wordmemory2; 3 = wordmemory3; 4 = wordmemory;]
</expt>

<expt>
/ subjects = (4 of 6)
/ groupassignment = groupnumber
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2 = wordmemory2; 3 = wordmemory; 4 = wordmemory3;]
</expt>

<expt>
/ subjects = (5 of 6)
/ groupassignment = groupnumber
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2 = wordmemory3; 3 = wordmemory; 4 = wordmemory2;]
</expt>

<expt>
/ subjects = (6 of 6)
/ groupassignment = groupnumber
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2 = wordmemory3; 3 = wordmemory2; 4 = wordmemory;]

If you want to treat the order of non-practice blocks (wordmemory to wordmemory3) as a between-subjects factor, then yes, that would be the way to do it.

If you merely want to randomize the order (not treating it as a systematic between-subjects manipulation), then you would simply make do with a single <expt> element:

<expt>
/ postinstructions = (end)
/ onexptend = [values.completed = 1]
/ blocks = [1 = wordmemory0; 2-4 = noreplace(wordmemory, wordmemory2, wordmemory3)]
</expt>

thank you

I wanted it to be a between-subject factor. I sent a link to my experiment to a few people via email but they all encountered the same block order, why is that?

I cannot answer that without (a) the relevant code from the script and (b) the link you sent out.

I have just sent you the link with the file so you can access the script. I could not copy paste the relevant syntax in the op however.