How do I create a freeze frame effect?

I want to create a freeze frame effect similar to the one shown in the below clip. Is that possible?

Yes. But you would need to do this in two steps.

First you need to create a screen grab of the point in the video at which you want to create the freeze frame effect. Then you would need to use that screen grab as part of your video.

Create screen grab

{
    "timeline": {
        "tracks": [
            {
                "clips": [
                    {
                        "asset": {
                            "type": "video",
                            "src": "https://shotstack-assets.s3.ap-southeast-2.amazonaws.com/footage/bmx.mp4",
                            "trim": 1.4
                        },
                        "start": 0,
                        "length": 1
                    }
                ]
            }
        ]
    },
    "output": {
        "format": "jpg",
        "resolution": "hd"
    }
}

Use screen grab in render

Notice that the first half of the video plays to second 1.4, then the screenshot is displayed at 1.4, the second video clip then is trimmed at 1.4 seconds.

{
    "timeline": {
        "cache": false,
        "soundtrack": {
            "src": "https://shotstack-assets.s3.ap-southeast-2.amazonaws.com/music/metal.mp3",
            "effect": "fadeOut"
        },
        "background": "#000000",
        "tracks": [
            {
                "clips": [
                    {
                        "asset": {
                            "type": "html",
                            "html": "<p><span>TEAM RIDER</span><br>JOEY MONEZ</p>",
                            "css": "p { color: #25d3d0; font-family: \"Montserrat ExtraBold\"; font-size: 40px; text-align: left; line-height: 70 } span { color: #ffffff; font-size: 22px; font-family: \"Montserrat SemiBold\" }",
                            "width": 400,
                            "height": 100
                        },
                        "start": 1.1,
                        "length": 2.5,
                        "offset": {
                            "x": -0.1,
                            "y": 0.15
                        },
                        "transition": {
                            "in": "slideRightFast",
                            "out": "slideLeftFast"
                        }
                    }
                ]
            },
            {
                "clips": [
                    {
                        "asset": {
                            "type": "image",
                            "src": "https://cdn.shotstack.io/au/stage/ccj9p58r3e/fe8885ef-e4b2-47df-bdb1-367514e25e59.jpg"
                        },
                        "start": 1.4,
                        "length": 2
                    }
                ]
            },
            {
                "clips": [
                    {
                        "asset": {
                            "type": "video",
                            "src": "https://shotstack-assets.s3.ap-southeast-2.amazonaws.com/footage/bmx.mp4"
                        },
                        "start": 0,
                        "length": 1.4,
                        "transition": {
                            "in": "fadeFast"
                        }
                    },
                    {
                        "asset": {
                            "type": "video",
                            "src": "https://shotstack-assets.s3.ap-southeast-2.amazonaws.com/footage/bmx.mp4",
                            "trim": 1.4
                        },
                        "start": 3.4,
                        "length": 3,
                        "transition": {
                            "out": "fadeFast"
                        }
                    }
                ]
            }
        ]
    },
    "output": {
        "format": "mp4",
        "resolution": "1080"
    }
}