Which command are you trying to run? Are you using the qiime2 plugin for picrust2? It looks like you need the sequences of the ASVs in your analysis. For that you want the FeatureData[Sequence] artifact which is often called rep-seqs.qza or something similar. The feature table in qiime2 does not usually store these sequences.
Thank you colin, I have obtained the FASTA file of the table using rep-seqs.qza file. Besides, I have obtained the biom file from table.qza file using commend below.
Actually, I'm encountering difficulties in preparing the filtered biom file for my PICRUSt2 analysis. I've come across recommendations for preprocessing steps like removing ASVs present in only one sample or samples with fewer than 30 ASVs. I'm wondering if there are any resources available where someone has already filtered the table for PICRUSt2 preprocessing? Additionally, I'd greatly appreciate it if someone could provide the QIIME2 commands necessary for conducting this filtering. Thank you!