For this type of lamp you will need bulb holder E14 for example here :
https://www.ledakce.cz/e14-objimka--sacek-card/?gclid=CjwKCAiA1uKMBhAGEiwAxzvX9-V8kFpODXoE3T1tCg7agqUBpSck83jNvwJD09oVo8ZG143tBdP2IhoCKOYQAvD_BwE