Without having any additional context, an appropriate translation is probably "Please contact me." or "Please keep in touch with me."
連絡 (れんらく, renraku) = contact
して (shite) is here used as an imperative form of する (suru, to do). Literally "Please do contact.", and the subject and object can be inferred. The ね (ne) at the end is a sentence-ending particle, but it doesn't really change the meaning much here. For more information about all kinds of particles here is an overview: https://www.tofugu.com/japanese/japanese-particles-cheatsheet/
Thanks a lot Jacobd2, I understand better and I have the idea of how to use it, for example in the sentence: 東京へいらっしゃったときは連絡してください.
So I'm telling you now: スペインへいらっしゃったときは連絡してください.
Regards
連絡してね
Hi!
I'm trying to understand in what cases is this expression used.
For example, is it an informal way of saying good bye , like "good bye, we keep in touch"
Thanks for your support