HTML code

1. Copy This CSS code and Paste it in Your Blogger Theme File

Start from here:-

/*--------YT-Responsive--css------*/

.ytiframe{

  position: relative;

  width: 100%;

  padding-bottom: 56.25%; 

  height: 0;

}

.ytiframe iframe{

  position: absolute;

  top:0;

  left: 0;

  width: 100%;

  height: 100%;

}

/*---xxx-----YT--Responsive-css---xxxx----*/

2. Copy This Embed Code and Paste it in HTML of Your Blog Post

Start from here:-

<div class="ytiframe"><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" frameborder="0" height="auto" src="https://www.youtube-nocookie.com/embed/VID-ID?rel=0" title="YouTube video player" width="100%"></iframe></div> 

3. Copy This Embed Code and add in blog post for Autoplay Video

Start from here:-

<div class="ytiframe"><iframe allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" frameborder="0" height="auto" src="https://www.youtube-nocookie.com/embed/VID-ID?&autoplay=1&rel=0" title="YouTube video player" width="100%"></iframe></div>

4. for instagram to embeded reel id

<blockquote class="instagram-media" data-instgrm-captioned data-instgrm-permalink="https://www.instagram.com/p/ REEL_ID/" data-instgrm-version="13"></blockquote>

<script async src="https://www.instagram.com/embed.js"></script>

5. linkedin video 

<iframe src="https://www.linkedin.com/embed/feed/update/urn:li:ugcPost:<video-post-id>" height="<height>" width="<width>" frameborder="0" allowfullscreen=""></iframe>

6. start and end video

<iframe width="560" height="315" src="https://www.youtube.com/embed/ABCDEFGHIJ#t=1m23s&end=2m45s" title="YouTube video player" frameborder="0" allow="accelerometer;

autoplay; clipboard-write;encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>