I disagree, verse 7 is loud and clear. Try it in the ESV
Jude 1:7 (English Standard Version)
7 just as Sodom and Gomorrah and the surrounding cities, which likewise indulged in sexual immorality and pursued unnatural desire, serve as an example by undergoing a punishment of eternal fire.
The fire has long gone out at Sodom and Gomorrah. However, the verse says they serve as an example of the eternalfire i.e. the second death.
Revelation 20:10-15 (New International Version)
10 And the devil, who deceived them, was thrown into the lake of burning sulfur, where the beast and the false prophet had been thrown. They will be tormented day and night for ever and ever.
The Dead Are Judged
11 Then I saw a great white throne and him who was seated on it. Earth and sky fled from his presence, and there was no place for them. 12 And I saw the dead, great and small, standing before the throne, and books were opened. Another book was opened, which is the book of life. The dead were judged according to what they had done as recorded in the books. 13 The sea gave up the dead that were in it, and death and Hades gave up the dead that were in them, and each person was judged according to what he had done. 14 Then death and Hades were thrown into the lake of fire. The lake of fire is the second death. 15 If anyone's name was not found written in the book of life, he was thrown into the lake of fire. Blessings, Stephen