thanks a lot, this is exactly what I was looking for.
I made a fastq_manifest.tsv as instructed then used it to import with the following code
qiime tools import \
--type 'SampleData[PairedEndSequencesWithQuality]' \
--input-path fastq_manifest.tsv \
--output-path pe-demux.qza \
--input-format PairedEndFastqManifestPhred33V2
I previously found the following page (Importing paired end demultiplexed MiSeq data) which is an older page explaining how to make a manifest but where links end dead as it was written for an old version of qiime. This is what I named dead link in my post.
thanks a lot, I can now proceed...