so i got a record on minecraft 1.15 random seed any percent glitchless of 45 minutes 23 seconds but i didnt record it what should i do to post it on the tab of minecraft 1.15 random seed

Well, if you didn't record anything, it will be very hard for you to prove it. Hmm.

Pretty sure the RSG WR is 21 minutes so no you didn't get a record.

From the Minecraft: Java Edition Game Rules:
"No time will be accepted without video proof. The video must not have any missing footage from creation of the world to finishing the run."

Need a video for most games or the run is unsubmitable. No vid, no did my friend

Do another run, but record it this time.

Free video recording tools if you need them:
1) OBS studio; very useful tool to both record and even stream your runs, works with any gpu
2) Nvidia shadowplay: simple to use tool to record anything with little to no degredation of quality from the run being played to the video, only available on Nvidia GPUs after gtx 600 series
3) Radeon ReLive: good for the same reasons as shadowplay, but for AMD gpus

you will need to record another run to submit it, you will not be granted a spot on the leaderboard without video footage