How to Create a Userstory from project 1 to project 2 in azure DevOps?

You can make use of below 2 Approaches to achieve your goal:-

Approach 1:- Azure CLI

Command:-

In this method you get a specific Work Item from source project and then use the output of the Get Work item to create new work item in another project

#make sure you login with your azure devops user account in the browser
az login

# Retrieve the details of an existing work item
$jsonoutput = az boards work-item show --id 93 --org https://dev.azure.com/sid24desai0738 

$jsonoutput

# Capture the output and use it to create a new work item
az boards work-item create --title "New Work Item1" --type "Task" --org https://dev.azure.com/sid24desai0738 --project "Agile" --description "Description of the new work item" --fields $jsonoutput.fields

Output:-
Destination Project:-

Approach 2:- Rest API

You can make use of Get Work Item with Project Name parameter set to the source project name then call Create Work Item API to create new Work Item similar to previous Get Work Item fields.

Approach 2:-

Powershell script to Get Work Item:-

$PAT = "35b3vduxekw2xmfvq2kwvlghb2ysss2du5qtgboosfp3rov6klqa"
$OrgName = "sid24desai0738"
$ProjectName = "AzureDevops"
$ApiVersion = "7.0"
$type = "Task"

$services = Invoke-RestMethod -Uri "https://dev.azure.com/sid24desai0738/AzureDevops/_apis/wit/workitems/3?api-version=7.1-preview.3" -Method Get -Headers @{Authorization=("Basic {0}" -f [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes(":$PAT")))}

$services

Output:-

Now use Create Work Item to create the Work Item from previous response:-

Sample Powershell code:-

# Set up authentication and project details
$PAT = "35b3xxxxxxx6klqa"
$OrgName = "sid24desai0738"
$ProjectName = "AzureDevops"
$ApiVersion = "7.0"

# Retrieve the original work item
$originalWorkItem = Invoke-RestMethod -Uri "https://dev.azure.com/$OrgName/$ProjectName/_apis/wit/workitems/3?api-version=$ApiVersion" -Method Get -Headers @{
    Authorization = "Basic " + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(":$PAT"))
}

# Extract necessary fields from the original work item
$title = $originalWorkItem.fields.'System.Title'
$areaPath = $originalWorkItem.fields.'System.AreaPath'
$iterationPath = $originalWorkItem.fields.'System.IterationPath'
$workItemType = $originalWorkItem.fields.'System.WorkItemType'
$state = $originalWorkItem.fields.'System.State'
$assignedTo = $originalWorkItem.fields.'System.AssignedTo'

# Define new project and type for the new work item
$newProjectName = "AnotherProject"
$newType = "Task"

# Create a new work item payload using the extracted fields
$newWorkItemData = @{
    'System.Title' = $title
    'System.AreaPath' = $areaPath
    'System.IterationPath' = $iterationPath
    'System.WorkItemType' = $workItemType
    'System.State' = $state
    'System.AssignedTo' = $assignedTo
    # Add other fields as needed
} | ConvertTo-Json

$newWorkItemData

# Define API parameters for creating the new work item
$newWorkItemUrl = "https://dev.azure.com/sid24desai0738/AzureDevops/_apis/wit/workitems/$newType?api-version=$ApiVersion"

try {
    # Create the new work item in the specified project
    $newWorkItem = Invoke-RestMethod -Uri $newWorkItemUrl -Method Post -Headers @{
        Authorization = "Basic " + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(":$PAT"))
        "Content-Type" = "application/json"
    } -Body $newWorkItemData -ErrorAction Stop

    Write-Output "New work item created successfully:"
    $newWorkItem
} catch {
    Write-Error "Error creating new work item: $_"
}

References:-

Work Items – Get Work Item – REST API (Azure DevOps Work Item Tracking) | Microsoft Learn

Work Items – Create – REST API (Azure DevOps Work Item Tracking) | Microsoft Learn

az boards work-item | Microsoft Learn