Sorry if this upsets you but...
↑ first attempt ( )
Try this flow (the URL and credentials were sanitised - they will need to be re-populated)...
[{"id":"5b278c8a8cf6ba6a","type":"http request","z":"950e6f56f9415563","name":"","method":"GET","ret":"bin","paytoqs":"ignore","url":"http://xxxxx.ddns.net:1240/ISAPI/Streaming/channels/1/picture","tls":"","persist":false,"proxy":"","authType":"digest","senderr":false,"x":960,"y":840,"wires":[["9b8400c7928d5f04","858d8023dd7b8a69"]]},{"id":"e28fbb96d41569de","type":"function","z":"950e6f56f9415563","name":"add headers","func":"msg.headers = {\n \"Accept\": \"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9\",\n \"Accept-Encoding\": \"gzip, deflate\",\n \"Accept-Language\": \"en-GB,en;q=0.9,en-US;q=0.8\",\n \"Cache-Control\": \"no-cache\",\n \"Connection\": \"keep-alive\",\n \"Host\": \"xxxxx.ddns.net:1240\",\n \"Pragma\": \"no-cache\",\n \"Upgrade-Insecure-Requests\": \"1\",\n \"User-Agent\": \"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.99 Safari/537.36 Edg/97.0.1072.69\",\n}\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":790,"y":840,"wires":[["5b278c8a8cf6ba6a"]]},{"id":"da3a017095ace603","type":"inject","z":"950e6f56f9415563","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{}","payloadType":"json","x":630,"y":840,"wires":[["e28fbb96d41569de"]]},{"id":"858d8023dd7b8a69","type":"debug","z":"950e6f56f9415563","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":1150,"y":800,"wires":[]}]