How to download incomplete m3u8 video

Question

Now I have an incomplete index.m3u8 file taken from the test video.

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:10.000000,
https://xxx/index0.ts
#EXTINF:10.000000,
https://xxx/index1.ts
#EXTINF:10.000000,
https://xxx/index2.ts
#EXTINF:10.000000,
https://xxx/index3.ts
#EXTINF:10.000000,
https://xxx/index4.ts
#EXTINF:10.000000,
https://xxx/index5.ts
#EXT-X-ENDLIST

After trying the last ts file is https://xxx/index40.ts, but I don't know the #EXTINF info from index6.ts to index40.ts (maybe some file is #EXTINF:9.8000000, or #EXTINF:8.0000000,...), so that the player can't play it normally.

Is there any way to solve this problem, or how can I download all ts file and combined to mp4 file in browser without saving the file in my backend server.

Thanks!