const options = {
method: 'PUT',
headers: {
customer: '<customer>',
'X-API-Key': '<api-key>',
'Content-Type': 'application/json'
},
body: JSON.stringify({crosslinkIds: ['<string>'], branchId: '<string>'})
};
fetch('https://backend.branch.flowengineering.com/project/{projectId}/entities/{entityId}/crosslinks', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));