Extracting frame timestamp (PTS) and seting it as a file name

I have a video file that lasts 9.3s and was recorded at FPS=10. I would like to use FFMPEG in order to extract frames from this video at arbitrary FPS (e.g. FPS=3). Example command:

ffmpeg -i input.mp4 -filter:v "fps=3" image_index_timestamp.jpg

But, I need to know which frame from original video FFMPEG has extracted. What I mean by that is, I would like to include in file name a timestamp (e.g. image_00_00:00:00.1.jpg, where 00 is index generated by FFMPEG and 00:00:00.1 is timestamp from which frame was extracted.).

I want to be able to SEEK to that specific timestamp and extract the same frame FFMPEG has generated for me.

By using following command I am able to draw timestamp (pts) on each frame. But, what I need is that timestamp inside filename and I dont know how to get it.

ffmpeg -i input.mp4 -filter:v "drawtext=fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf: text='%{pts\:hms}': x=(w-tw)/2: y=h-(2*lh): fontcolor=red: box=1: boxcolor=0x00000000@1,fps=3" -start_number 0 image_%03d.jpg

ffmpeg docs suggests this to timestamp ALL frames- ffmpeg -i input.mp4 -f image2 -frame_pts true %d.jpg

If you check out https://ffmpeg.org/ffmpeg-all.html and search for "expand the filename with pts"

but I dont think its the true Presentation Time Stamp, rather its an index.