Making fasta files from gtf and reference genome

Question

[Olajucan]

Hi, I'm working on RNAseq data analysis.

I used HISAT2 and Stringtie to make reference transcriptome and gtf files.

Since my material is wheat, whose reference genome was released a month ago but annotation isn't completed yet,

I have to extract sequences of transcripts as fasta format to annotate them.

For that purpose, Is GFF utilities working on that?

Or, have any good ideas for annotating transcripts?